Regression test that deserializes every spawned JSON file under
Data/Spawns/ via SpawnerDto, calls ToSpawner() to build the live
spawner, and deletes it to prevent world leaks. Catches both JSON
deserialization failures and exceptions during spawner construction,
collecting failures per file. Any failure names the offending file
and is a real migration defect, not a test weakness.
All 484 tests pass including the new AllSpawnFilesLoadTests.
Remove (DynamicJson, options) constructors and ToJson(DynamicJson, ...) methods
from BaseSpawner, Spawner, RegionSpawner, and ProximitySpawner. Delete
DynamicJson.cs entirely. Remove now-unused using Server.Json and
using System.Text.Json directives from all four files.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
tools/spawner-json-migrate/migrate.mjs was a one-time offline script to
rename "type"->"$type" and convert homeRange->spawnBounds in spawn data.
Migration is complete; the tool is no longer needed.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- Rename "type" -> "$type" (first key, required for STJ polymorphism) in
all 109 spawn JSON files (5,612 records).
- Convert "homeRange" + "location" -> "spawnBounds" object, dropping homeRange.
Runtime keeps reading homeRange so un-migrated/external files still load.
- Add BoundsEquivalenceTests (hr=0/1/3/7) validating that the script's toBounds
formula produces the same Rectangle3D as the runtime homeRange path.
- Add MigratedDataLoadTests loading a real migrated file as List<SpawnerDto>
and round-tripping each DTO through ToSpawner().
- Add tools/spawner-json-migrate/migrate.mjs (offline Node script).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
CreateEmpty() registers the Item in the world before population. If ApplyDto
or subtype-field application throws, the import catch cannot reach the (unassigned)
spawner local, re-opening the orphan leak Approach B prevents. Wrap population in
try/catch in the base ToSpawner() and all three overrides: on failure Delete() the
single Item and rethrow, so the import path only counts the failure.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Direct-to-Item deserialization leaks orphaned world Items on malformed input
(STJ constructs Items before validation). Pivot to plain record DTOs +
ToSpawner()/ToDto() so failure is GC-only. Revise spec §0 + add v2 plan.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
- Add ImportLocation/ImportMap read-only accessors to BaseSpawner.Json.cs
exposing _jsonLocation/_jsonMap for the importer post-STJ-deserialization.
- Rewrite ImportJsonSpawners to deserialize List<BaseSpawner> directly via
SpawnerJsonSerializer.Options (polymorphic on $type), eliminating
DynamicJson + AssemblyHandler.FindTypeByName + CreateInstance<ISpawner>.
- Enforce cleanup contract: every deserialized spawner (registered in World
at Map.Internal by STJ) is either MoveToWorld'd or Delete()'d — map==null/
Internal guard Deletes, inner catch Deletes on placement failure.
- Add internal ImportFile seam for testability (from=null safe; only used in
JsonException path which valid files never hit).
- Add ImportCleanupTests: valid placement, no-map orphan rejected, duplicate
location replaced — all with rigorous finally cleanup.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Rewire ExportSpawnersCommand.ExecuteList to build List<BaseSpawner>
and serialize via SpawnerJsonSerializer.Options instead of the
DynamicJson.Create + spawner.ToJson loop. Add file serialize→deserialize
round-trip test with exception-safe cleanup.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Add regression tests for homeRange property conversion on deserialize.
Tests verify that legacy JSON with homeRange field (no spawnBounds)
deserializes to centered Rectangle3D bounds as implemented in
BaseSpawner.OnAfterJsonDeserialize.
- homeRange: 3 -> Rectangle3D(97, 197, -128, 7, 7, 256)
- homeRange: 0 -> Rectangle3D(100, 200, 5, 1, 1, 0)
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
- Add ProximitySpawner.Json.cs with shadow properties for triggerRange,
spawnMessage, and instant; OnAfterJsonDeserialize calls base then applies them
- Mark ProximitySpawner [JsonDiscoverableType] and its parameterless ctor
[JsonConstructor] for STJ polymorphism discovery
- Add ProximitySpawnerRoundTripTests with test-hygiene finally cleanup
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Move spawner?.Delete() into the finally block so a placed (MoveToWorld'd)
spawner cannot leak into shared "Sequential UOContent Tests" map state if
an assertion throws. Declare spawner/s before the try and null-init them.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Add RegionSpawner.Json.cs with a `region` shadow property (serializes
SpawnRegion.Name) and OnAfterJsonDeserialize override that resolves the
region by name using _jsonMap from BaseSpawner. Mark RegionSpawner with
[JsonDiscoverableType] and [JsonConstructor] on its parameterless ctor
so SpawnerJsonSerializer discovers it for STJ polymorphism.
Add RegionSpawnerRoundTripTests: create+register a test BaseRegion on
Felucca (game regions are not loaded in the test environment), serialize
a RegionSpawner, assert $type and region name in JSON, deserialize, and
assert SpawnRegion.Name round-trips correctly. RED → GREEN confirmed.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Implements Task 2 of the spawner STJ migration:
- SpawnerJsonSerializer: assembly discovery of [JsonDiscoverableType]-marked
BaseSpawner subclasses, STJ polymorphism on $type, property pruning to
[JsonPropertyName]-only, and OnDeserialized→OnAfterJsonDeserialize() hook.
- BaseSpawner.Json.cs: shadow JSON properties for all BaseSpawner fields,
OnAfterJsonDeserialize() virtual method that applies deserialized state.
- Spawner.Json.cs: JsonSpawnBounds shadow property, override of
OnAfterJsonDeserialize() to apply spawnBounds after base.
- Spawner.cs: [JsonDiscoverableType] + [JsonConstructor] on parameterless ctor.
- TestServerInitializer: SpawnerJsonSerializer.Configure() wired in.
- SpawnerRoundTripTests: 2 tests (round-trip core fields, omits domain defaults).
Old DynamicJson ctors and ToJson() left in place; removal is Task 9.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Design + step-by-step plan to delete DynamicJson and migrate spawners to
typed System.Text.Json (discovery-based polymorphism, $type discriminator).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
## Problem
A creature equipped with two items that resolve to the **same layer** can crash the legacy EA 2D client (use-after-free). Equipment `Layer` comes from tiledata (`Layer = (Layer)ItemData.Quality`), so a **two-handed weapon and a shield both resolve to `Layer.TwoHanded`**. `Mobile.FindItemOnLayer` even documents the invariant: *"We only allow 1 item per layer. Its an implicit contract."*
## Root cause
- `SendMobileIncoming` (0x78) **dedupes by layer** (the `layers` span) and sends only the first item per slot — so a static creature is fine.
- But the per-item **`SendEquipUpdate` (0x2E)** and the item **OPL** sends do **not** dedupe. On any equip/property delta (`Item.ProcessDelta`) they fire per item and leak the second same-layer item on its own.
- The client then holds two items on one equipment slot; when that slot is torn down (e.g. a large group of such creatures and the player runs out of range → mass remove) the legacy 2D client frees one and dereferences it → UAF. ClassicUO bounds-checks and is unaffected, but the server is emitting an invalid, self-contradictory stream either way.
## Fix
Make per-item equip/OPL sends honor the same first-item-per-layer rule `SendMobileIncoming` already uses:
- `Item.IsDupedEquipLayer()` — `m_Parent is Mobile m && m.FindItemOnLayer(m_Layer) != this` (reuses the existing helper; true when an earlier item already holds this items layer).
- `Item.ProcessDelta`: early-return before the per-client loop for a duped equipped item (skips the EquipUpdate and OPL to everyone).
- `Mobile` lift-reject re-show: skip the EquipUpdate and OPL for the dupe.
No behavioral change for valid equipment (distinct layers → never duped). For the invalid duped-layer case the second item was already omitted by the 0x78 packet; this just stops it leaking back via the per-item paths.
## Summary
House customization rejected ~40% of components — all classic/base tiles such as **sandstone** — for non-staff players. The pieces appeared briefly in the editor, then vanished before commit; only staff (GM+) could add them.
## Root cause
A data-convention mismatch introduced when housing.bin support was added (#2329).
- The OSI `housing.bin` encodes pre-AOS base pieces with the client **T2A** feature bit (`0x1`).
- `walls.txt` (and RunUO) encode the same pieces as `FeatureMask = 0` (always valid).
- `ComponentVerification.CheckValidity` validates against `ExpansionInfo.HousingFlags`, whose enum has no `0x1` bit, so base pieces failed `(HousingFlags & 0x1) != 0`.
- `HouseFoundation.Designer_Build` only enforces `ValidPiece` for `AccessLevel < GameMaster`, so staff bypassed validation while players had placements rejected — the server re-sends the design state and the client rebuilds the house from it, erasing the just-placed piece.
This only affects servers loading `housing.bin` from a UOP client; the old txt-only path (pre-#2329, like RunUO) was unaffected because base pieces are `0` there.
## Fix
Normalize the `housing.bin` feature mask to the housing-tier bits on load (`& HousingFlags.HousingEJ`). Base pieces collapse to `0` (always valid, exactly as `walls.txt` encodes them); `AOS`/`SE`/`ML`/... pass through unchanged. Both data sources now produce an identical validity table, matching RunUO behavior. `CheckValidity` and the `val != -1` anti-cheat guard are unchanged.
## Verification
- Parsed the real `housing.bin` from a 7.0.x client: sandstone (`0x345`) loads as `0x1` → `& HousingEJ` → `0` → valid; tier pieces (`0x40` SE, etc.) pass through; unregistered tiles stay `-1` → rejected.
- Confirmed OSI's own files disagree for the same pieces: `walls.txt` base `FeatureMask = 0` vs `housing.bin` `0x1`.
- `dotnet build` clean (0 warnings, 0 errors).
## Summary
Streamlines the SE-era archery ammo auto-recovery (recovering spent arrows/bolts after a miss). The mechanic was previously spread across four unrelated trigger points and a weapon-scoped timer that was divorced from the recovery state living on `PlayerMobile`. It also contained dead code.
### Problems fixed
- **Dead `!Warmode` gate** — `OnMiss` only runs from `OnSwing`, which requires warmode to fire, so the `if (!pm.Warmode)` branch that started the recovery timer could never trigger.
- **Scattered, divorced state** — banked ammo lived on `PlayerMobile.RecoverableAmmo` while the timer lived on the weapon (`_recoveryTimerToken`), and recovery was kicked off from four different places (`OnWarmodeChanged`, `PlayerMobile.OnDamage` kill, `BaseCreature.OnDamage` kill, `OnBeforeDeath`).
- **Per-player footprint** — every `PlayerMobile` carried a `RecoverableAmmo` field even though ~99% never miss with a bow (and most are offline).
### New design — `AmmoRecovery` side table
- All state (banked ammo + one repeating timer) is keyed by player in a static dictionary, so only players who actually miss carry any state. Transient by design — this was never serialized.
- **One feed point:** `OnMiss` banks the spent ammo type and starts the player's timer.
- **One drain point:** the timer self-gates and gathers ammo into the backpack only once the archer has disengaged — **alive, out of warmode, and not running** — otherwise it retries next tick, so banked ammo is never lost while online.
- **"Not running" allows standing still _or_ walking.** The `Direction.Running` bit is stale after a player stops, so it's paired with movement recency (`LastMoveTime`); only an *actively* running archer is blocked.
- Removed the redundant scattered triggers, the dead `!Warmode` branch, `RecoverableAmmo`, `RecoverAmmo()`, and the now-empty `OnWarmodeChanged` override. `PlayerMobile.OnDelete` calls `AmmoRecovery.Forget`.
### Behavior notes
- On death, banked ammo is **no longer flushed to the corpse** — it stays banked and is recovered after resurrection once the archer settles (player keeps it rather than dropping it to looters).
- `OnHit` immediate recovery (the ~40% arrow-to-defender behavior) is **unchanged**.
## Test plan
- [x] `dotnet build Projects/UOContent/UOContent.csproj -c Release` — succeeds, 0 warnings, 0 errors.
- [ ] In-game (SE era): miss bow shots, then disengage (drop warmode + stop) and confirm the "You recover N arrows/bolts" message and backpack contents; confirm recovery does **not** fire while running and **does** while walking/standing.
## What
- **BuildTool now has a distinct application icon** — the MUO mark with a three-gear "settings" cluster in the bottom-right, colored by size (azure / steel / teal), wired in via `<ApplicationIcon>` in `BuildTool.csproj`. This differentiates the (now signed) build tool from the server in the taskbar/Explorer.
- **Refreshed `Projects/Application/MUO.ico`** — re-rendered from vector with the full Windows size ladder (16/32/48/64/128/256). The previous icon only carried 128/256 frames, so Windows had nothing proper for small sizes.
- **Added `branding/`** — the source SVGs (`muo.svg`, `gears.svg`, `build-tool.svg`) the `.ico` files are rasterized from.
## How
Both icons are rasterized from the branding SVGs (high-density render → Lanczos downscale per frame → packed into a 6-frame `.ico`). The rasterization script and its node deps are kept local under the gitignored `tools/` dir and intentionally not committed — `branding/` is the source of truth.
## Verification
- `dotnet build Projects/BuildTool/BuildTool.csproj` succeeds (0 warnings/errors).
- The embedded icon resource extracts from the produced `build-tool.exe`.
- Both `.ico`s validate as 6-frame Windows icons.
### Icons
<img width="150" height="150" alt="build-tool" src="https://github.com/user-attachments/assets/9c443947-4c26-46a3-ad9b-5f50630d90ad" />
## Summary
Audit of CI/CD workflows (`.github/workflows/**`, `azure-pipelines.yml`) for outdated actions, focused on the Node 20 → Node 24 runner deprecation. Most actions were already migrated; this PR cleans up the remaining stragglers and closes the gap that let them drift.
## Changes
| Action | File(s) | From | To | Reason |
|---|---|---|---|---|
| `softprops/action-gh-release` | `create-release.yml`, `build-tool-release.yml` | `v2` | `v3` | v2 still runs Node 20; v3 is a pure Node 24 runtime move, inputs unchanged (drop-in) |
| `dotnet/nbgv` | `create-release.yml` | `v0.5.1` | `v0.5.2` | Node 24 runtime bump |
| `SethCohen/github-releases-to-discord` | `post-release-discord.yml` | `v1.19.0` | `v1.20.0` | Latest; adds manual-dispatch test support |
| Dependabot | `dependabot.yml` | nuget only | + `github-actions` (weekly) | Auto-PR future action bumps instead of manual audits |
## Already current (no change)
`actions/checkout@v6`, `actions/setup-dotnet@v5`, `actions/upload-artifact@v7`, `actions/download-artifact@v8`, and `signpath/...@v2` are all on current majors running the Node 24 runtime. The Azure tasks (`UseDotNet@2`, `NuGetAuthenticate@1`) are current as well.
## Notes
- All target versions verified against GitHub's release API.
- `action-gh-release@v3` release notes confirm it's a runtime-only change with no input/behavior changes — safe drop-in for both usages.
## Problem
Houses and boats (multis) were pathed correctly only by **delegation to the slow path**: `StepCache.TryGetMask` returns `Fallthrough_Multi` for any multi-covered cell, and `GetSuccessors` ran `CheckMovement` **8× per cell** (each re-resolving the tile stack via `GetStaticAndMultiTiles`) — a sustained per-step cost near every house/boat. There was also no automated test pinning multi pathfinding.
This branch is the full multi-pathfinding effort in phases on one branch.
## Phase 1 — characterization tests (the oracle)
Implementation-agnostic invariants: a cache-on≡cache-off whole-path invariant, a per-cell sweep vs `CheckMovement` over footprint+halo (incl. destination Z), hand-verified routing (around walls, demolish-reopens, foundation-redesign-honored), classic-house / foundation / boat fixtures, non-vacuity guards. These gate every later phase byte-for-byte.
## Phase 2 — live single-pass synthesizer
`StepProbe.ComputeMultiMaskAt` synthesizes a covered cell's full 8-direction `StepMask` in one pass (the existing surface/step logic over `GetStaticAndMultiTiles` instead of 8× `CheckMovement`). `GetSuccessors` routes `Fallthrough_Multi` cells through it. No new cache, no `.swb` change. **~1.5×**, zero added allocations.
## Phase 3 / 3.1 — warm per-`multiID` interior cache (airtight)
`MultiMaskCache` caches each fixed multi's local-frame `StepMask` for **interior** cells (cell + all 8 neighbours covered → terrain-neighbour-free → position-invariant), keyed by `multiID & 0x3FFF`, built lazily from the MCL. Interior cells become ~20 ns lookups.
The cache is gated on a **per-instance footprint-clean flag** (`BaseMulti.PathInteriorCacheState`): an instance whose whole footprint terrain is below its floor (`maxTerrain < minFloor`) serves from the cache; a **dirty** instance (terrain intrudes — a contrived/GM placement) **degrades to live-synth, never a wrong mask**. This closes a cross-instance soundness gap (the cached mask depends on neighbour terrain too) found in a holistic review. The gate resets whenever the footprint's world-terrain relationship can change — **location, map, or ItemID** (a boat's heading swaps the MCL).
**Boats are cached too.** Their per-`multiID` deck masks are movement-invariant (built once per heading), so a sailing boat never rebuilds them; only the cheap clean-flag rescan repeats per move (and only when pathed near). Narrow existing boats have little interior; wide galleons (`multi.mul`) would gain Castle-class. `HouseFoundation` (per-instance runtime `DesignState`) is the one type that stays on the live path.
## Verification
- `UOContent.Tests` **454/454**, `Server.Tests` **708/708**, 0 failures.
- The Phase-1 oracle (`MultiPathInvariantTests`, cache-on ≡ cache-off) stays **byte-identical** with the synthesizer + interior cache active.
- Tests pin: footprint-cleanliness (clean vs sunk), dirty/cluttered placement degrades to live-synth while still pathing, clean placement serves, and the gate resets on move/ItemID change.
## Performance (modernuo/ModernUO-Benchmarks#8, full-fixture)
Houses at **Green Acres** (flat staff region → clean footprints, the legit-placement case):
| Route | Slow path | Phase 3.1 (interior cache) | Speedup |
|-------|----------:|---------------------------:|--------:|
| `around_a` (29 steps) | 238.3 µs | **49.1 µs** | **4.85×** |
| `around_b` (29 steps) | 224.3 µs | **49.5 µs** | **4.53×** |
~130 of ~167 multi cells/route serve from the cache (~20 ns) vs 37 live-synth. Per-cell, the slow path's 8× `CheckMovement` grows with multi complexity (GuildHouse ~857 ns → Castle ~1,194 ns), the synthesizer is a flat ~780 ns, and the cache serve is ~20 ns — so big/tall multis (and wide galleons) gain most. Identical allocations throughout.
## Summary
`Mobile.SayTo(Mobile to, int number, string args = "")` always sends the localized message using `SpeechHue`. This adds a parallel overload that accepts an explicit `hue`:
```csharp
public void SayTo(Mobile to, int number, int hue, string args = "") =>
to.NetState.SendMessageLocalized(Serial, Body, MessageType.Regular, hue, 3, number, Name, args);
```
It mirrors the existing localized overload exactly, only substituting the caller-provided `hue` for `SpeechHue`, so content can send a cliloc message to a single mobile in a chosen color without dropping down to `NetState.SendMessageLocalized` directly. This restores the hued-cliloc `SayTo` that RunUO/ServUO content commonly relied on (e.g. `SayTo(from, 1042205, 0x3B2)`).
## Notes
- Purely additive; no behavior change to existing call sites.
- No overload ambiguity: `SayTo(m, num)` and `SayTo(m, num, "args")` still bind to the existing overload; `SayTo(m, num, hue)` binds to the new one (the third positional arg is `int` vs `string`).
- Null-safe to the same degree as the existing overload (`SendMessageLocalized` guards via `CannotSendPackets()`).
## Test Plan
- [x] `dotnet build Projects/Server` — 0 warnings, 0 errors.
- One-line additive overload mirroring an existing (untested) method; no existing `Mobile.SayTo` unit tests to extend. Happy to add coverage if preferred.
Fixes#1690. Addresses Blood Oath holistically — three bugs found while researching the spell against RunUO, ServUO, the UODemise/uo.com guides, and the archived UOGuide page.
## Bugs fixed
### 1. Expiry timing (the filed issue)
The `ExpireTimer` polled every 1s, so expiry and death/delete cleanup lagged up to ~1s. Replaced with a **single-shot** timer plus centralized `[OnEvent]` handlers on `PlayerDeathEvent`/`PlayerDeletedEvent`/`CreatureDeathEvent`/`CreatureDeletedEvent` — the oath now breaks immediately on death/delete of either party.
### 2. Duration formula
Used `/80` (the bugged in-game tooltip value) instead of the real OSI formula `((SpiritSpeak - Resist) / 8) + 8`. Confirmed by RunUO, ServUO, the emulator guides, and the code's own fixed-point comment. At GM Spirit Speak this changes duration from ~9.5s to 23s and makes Spirit Speak actually affect duration.
### 3. Damage reflection (`BaseCreature.Damage` vs `PlayerMobile.Damage`)
`BaseCreature.Damage` diverged: it attributed the reflected hit to the attacker itself (`from.Damage(amount, from)`) instead of the caster, reflected the bonused (not original) amount, used `×1.1` vs `×1.2`, lacked the caster-survival guard, and had no Publish 48 resist mitigation.
Unified both paths: reflect the **original** damage attributed to the **caster** at `×1.2`. Publish 48 resist mitigation now applies only to creature casters and is gated behind `Core.SA`.
## Internals
- Collapsed the parallel `_oathTable` into a single `_table` keyed by both participants → shared timer, so `RemoveCurse` resolves from either side (required by the event handlers).
- Extracted `GetDurationSeconds` and `ComputeReflectedDamage` as testable statics.
## Tests
13 new tests (duration formula, reflection mitigation, oath lifecycle, end-to-end event-driven removal). Full suite: **436/436 pass**.
## Summary
Fixes the pathfinding step-cache (`.swb`) prebake so it bakes **once** and skips when a valid cache already exists, instead of re-baking on every boot. The root cause was the staleness fingerprint hashing mutable in-memory tile data rather than the on-disk files. This PR makes the fingerprint a pure function of the client data files and separates dynamic multis (houses/boats) from the static cache.
> This branch builds on the `ConfigurePrompts` first-boot-prompt unification (commit `5df8d0bd`, also included here) — that commit accounts for the `ServerConfiguration.cs` and `dev-docs/server-lifecycle.md` changes in the diff.
## The bug
With `pathfinding.prebakeMaps` set, the cache re-baked on **every** boot. The `.swb` staleness fingerprint hashed the live `TileData.LandTable`/`ItemTable` flags, which the server patches at runtime (`ItemFixes`, `LOSBlocker`, `PotionKeg`, `CTF`) at nondeterministic lifecycle points (Initialize-phase methods share a priority; static ctors fire lazily). So a fingerprint stamped at runtime (`[PathBake`) never matched the one recomputed during startup `Initialize()`, and the cache rebaked every time.
## Changes
**1. Fingerprint the files, not the in-memory tables** (`fix`)
Hash `tiledata.mul` (cached, computed once) plus the per-map `.mul`/`.uop` files — never the runtime-mutated `TileData` tables. The fingerprint is now lifecycle-stable. Existing `.swb` files rebake once after deploy, then stay stable.
**2. Compute the fingerprint once per boot** (`refactor`)
`Configure()`'s `AutoLoadAtStartup()` already opens and fingerprint-validates a reader for every up-to-date `.swb`. `Initialize()` now skips baking any map that already has an open reader (`StepCache.HasLazyReader`) instead of recomputing the fingerprint a second time.
**3. Bake static-only; route multis to the live path** (`refactor`)
Multis (houses/boats) are dynamic, so they're no longer baked into the static chunk cache — they were tagged with `BuiltMultisVersion`, a non-persisted session counter, which made persisting them unsafe (false matches / wasted re-bakes).
- Chunks bake land + `statics.mul` only.
- At query time, any cell whose sector (or its 1-cell halo) contains a multi routes to `Fallthrough_Multi` → the existing live, multi-aware `CheckMovement` path. The halo prevents a cell proposing a walkable edge into a neighbouring wall; interior (multi-free) cells pay one sector lookup.
- Adds `Sector.HasMultis` (one engine accessor); `.swb` format → v9 (rejects old multi-baked files); new `Fallthrough_Multi` telemetry.
- Behaviour-preserving: multis use the same live path the engine used before the cache existed.
**4. Comment polish** (`style`) — no behaviour change.
## Testing
All green: **92** pathfinding (incl. a new fingerprint-stability test and a multi-halo fallthrough test), **423** UOContent, **708** Server.
## Follow-ups (not in this PR)
- **Background bake worker** — make `[PathBake` and the boot prebake non-blocking (game thread serves tile reads to an off-thread worker).
- **Per-multi MCL cache** — cache walkability in each multi's own frame (keyed by multiID, movement-invariant) so houses/boats get a fast path instead of the live fallback.
- **House-pathfinding equivalence tests** — the one area not yet covered by a dedicated automated test; multi pathing is currently correct by delegation to the live path.
Stacked on #2475 (the `ConfigurePrompts` phase). Base will switch to `main` once #2475 merges.
## What
Move the engine's own first-boot prompts — data directories, listeners, server name, expansion + map selection — out of `ServerConfiguration.Load` and into **`ServerConfiguration.ConfigurePrompts()`** (`[CallPriority(0)]`), so **all** first-boot prompting (engine and content) runs through the single `AssemblyHandler.Invoke("ConfigurePrompts")` phase. `Load` now only reads/creates the config file.
## Why it's safe
- **Assembly loading uses `AssemblyDirectories` (default `./Assemblies`), not `DataDirectories`** — so assemblies load fine before the now-later data-dir prompt. This is the linchpin that makes the move possible.
- **`UOClient.Load()`** (client-file discovery via `Core.FindDataFile`) needs `DataDirectories`, so it moved *with* the data-dir prompt into `ConfigurePrompts`.
- **`Core.Expansion`** is now assigned in `ConfigurePrompts` (every non-mocked boot). Nothing between `LoadAssemblies` and that phase reads it — type initializers run lazily on first use, not during `LoadAssemblies`.
- **`[CallPriority(0)]`** keeps the engine prompts (including map selection) ahead of content prompts such as the pathfinding pre-bake (priority 50), preserving "after map selection".
- `Main.cs` already invokes the phase — **no startup-ordering edit** here.
## Tests
`Server.Tests` **708/708**, `UOContent.Tests` **418/418**, build clean. Fixtures are unaffected: they call `Load(true)` (now just reads config) and set expansion/data dirs directly; `ConfigurePrompts` is gated on `m_Mocked`.
## ⚠️ Needs first-boot runtime verification
`Main.cs` startup ordering is **not** covered by the fixture-based suite (the fixtures bypass `Main`). Please boot once with a fresh `modernuo.json` to confirm the first-boot prompt sequence (data dirs → … → expansion/maps → pathfinding pre-bake) and that `Core.Expansion` resolves correctly. Docs updated in `dev-docs/server-lifecycle.md`.
## Summary
Adds authentic **T2A-era (pre-UO:Third-Dawn) packet-based crafting menus**, enabled via the **`t2aCraftMenus` server setting** (read once at startup; default **`!Core.UOTD`**, so a pre-UO:TD shard gets them automatically). When enabled, double-clicking a crafting tool opens the classic `0x7C`/`0x7D` item-list menu — skill- and material-filtered — instead of the modern gump, covering all 8 tool/skill crafts (blacksmithy, tailoring, tinkering, carpentry, alchemy, bowcraft/fletching, inscription, cartography). It is **not** a runtime/admin-flippable feature flag.
This is the **definitive, reconciled** branch and **supersedes**:
- **#2181** (Delphi — `T2A_CraftingMenus`): the original effort.
- **#2381** (Jack/UOLL — `t2a_crafting_menus`): the research-grounded superset (Delphi's base + 12 corrections), rebased onto current `main`.
Original authorship is preserved across the cherry-picked history: foundation commit **@Delphi79**, mechanic fixes **@jackuoll (Jack Ward)**, reconciliation/fixes/docs mine.
## How it was built
1. Cherry-picked Jack's 13 commits onto current `main` (superset of Delphi's; only 2 trivial FeatureFlags conflicts).
2. Applied targeted fixes (below) with tests.
3. Full convention audit, build, and test pass.
Grounded in independent historical research plus Jack's deep dive. Maintainer reference: `dev-docs/t2a-crafting.md`.
## Mechanics (highlights)
- Double-click tool → target resource → skill/material-filtered menu → craft. Resource pre-selection per skill; make-last by targeting the tool.
- **Stacked-gem jewelry:** target a gem stack → the **full stack** is consumed and the piece is named by count ("a 1000 diamond ring"); count persists (`BaseJewel` serialization **v4 → v5**, new `_gemCount`).
- **Tool-less inscription & cartography** (skill-list invoked; no pen/sextant); inscription consumes reagents+scroll on success and failure, mana only on success.
- **Tailoring matching-hue consumption:** targeting hued cloth/leather consumes only that hue. Crafted items take color from their **`CraftResource`** (not the dyed hue), so dyed leather/cloth don't tint the product; in T2A only colored ingots/ore color items (metal armor/shields).
- **Half-resources on failed non-scroll crafts** (pre-UO:TD).
- **Maker's mark** always prompted for exceptional items, via the shared `QueryMakersMarkGump`.
- Server-side menu infra changes are additive (`ItemListEntry.CraftIndex`, `Entries` setter, `HasSent`).
## Notable changes on top of the cherry-pick
- **Toggle is a startup server setting, not a feature flag.** Removed `ContentFeatureFlags.T2ACraftMenus` (and its admin-flippable plumbing); the value is read once via `ServerConfiguration.GetSetting("t2aCraftMenus", !Core.UOTD)` into `T2ACraftSystem.Enabled`. Since the default tracks the era and it can't be flipped at runtime, there's no incoherent "menus-on / UO:TD-era" state.
- **Stacked-gem consumption (B3a/B3):** consume the full `PendingGemCount` (was deliberately consuming 1 while naming by the stack), null-safe gem type, plain-piece fallback + message. New `T2AJewelGemCraftTests`.
- **Convention audit:** `new List<Item>()` → `PooledRefList<Item>` on the hue-aware consume path; removed dead code.
## Decisions & deviations
- `make-last` kept as **QoL** (post-T2A gump-era feature).
- `half-on-failure` (non-scroll) kept as a **reconstruction** (not OSI-confirmed).
- **Stacked-gem** behavior set per shard authority (overrides the "single gem" reconstruction).
- **Cooking** out of scope (no T2A crafting menu existed for it).
- **No colored items from dyed materials:** crafted color comes from the `CraftResource` type. Pre-AOS leather has no colored variant, so leather is always uncolored; weapons retain resource color only in AOS+ (unchanged, intended).
## Test plan
- Automated: `dotnet build ModernUO.slnx -c Debug` clean; `dotnet test Projects/UOContent.Tests` → **421 passed** (incl. 3 new jewelry tests).
- Manual (needs a running T2A shard + client):
- [ ] Each of the 8 skills opens the correct menu; empty-menu guard fires.
- [ ] Make-last repeats the last craft (jewelry re-prompts gem).
- [ ] Jewelry consumes the full targeted gem stack and names by count.
- [ ] Cartography consumes blank maps only with T2A enabled / maps+scrolls when disabled.
- [ ] Tailoring consumes only the targeted-hue material; crafted items are not tinted by dyed cloth/leather.
- [ ] Maker's-mark prompt on exceptional.
- [ ] Failed non-scroll craft consumes half resources.
- [ ] Inscription: reagents+scroll on success/failure, mana only on success.
- [ ] T2A disabled: gump crafting unchanged.
## Credits
Co-authored-by: @Delphi79
Co-authored-by: @jackuoll
## What
On **first boot** (right after map selection), offer to pre-bake the pathfinding `.swb` cache for the selected maps. This removes first-pathfind-after-boot latency and is now cheap — ~18 MB/facet after the v8 format work (the old ~565 MB is gone). The answer persists in `modernuo.json` as **`pathfinding.prebakeMaps`** (default **false**): asked exactly once, and skipped on headless/CI boots (redirected input) where operators can set the flag directly.
## How — a generic startup phase, not pathfinding hardcoded in the engine
The clean-console (pre-Serilog) prompt window is inside the engine startup, but UOContent isn't loaded until after `ServerConfiguration.Load`. So rather than coupling the engine to pathfinding, this adds a generic lifecycle phase:
- **`Main.cs`**: new `AssemblyHandler.Invoke("ConfigurePrompts")` — runs **after** `LoadAssemblies` (so content can participate) but **before** the first `logger.Information` (so console prompts aren't interleaved with the async console sink). The first log line moves below it. Any class can hook in with `public static void ConfigurePrompts()` and self-gate on first-boot state. No `ServerConfiguration` or pathfinding coupling added to the engine.
- **`PathCacheCommands.ConfigurePrompts()`**: the first-boot prompt (interactive-only, flag-absent-only); persists the answer.
- **`PathCacheCommands.Initialize()`** (`Invoke("Initialize")` phase, after the tile matrix loads — which the bake walks): when the flag is set, bakes any map whose `.swb` is **missing or stale** (tile-data fingerprint mismatch, via `StepCache.ComputeLiveFingerprint` / `TryReadFingerprintFromFile`). A fresh cache is a no-op, so only the first boot — or a post-client-update boot — pays the several-minute cost.
## Docs
Fixed the now-stale "~565 MB / ~1.5–2 GB / do not bake by default" section in `dev-docs/pathfinding.md` (it's 17.9 MB for Trammel, tens of MB for all six facets after v8), added a "First-boot pre-bake prompt" section, and added the `pathfinding.prebakeMaps` lever row.
## Verified
- `dotnet build UOContent -c Release` → 0 errors (rebased on #2474).
- Pathfinding/StepCache tests: **90/90 pass**.
- Bootstrap streamlining of the startup phases is intentionally left as a follow-up.
## Problem
Running the full `UOContent.Tests` suite, the test host **hangs ~2.5 minutes at shutdown and then crashes** (`Test host process crashed` / run aborted). The tests themselves are fine — they complete in ~1s — but the process can't exit.
Captured via `--blame-hang` dump. The blocking thread:
```
System.Threading.WaitHandle.WaitOne()
Server.SerializationThreadWorker.Sleep() SerializationThreadWorker.cs:54 (_stopEvent.WaitOne())
Server.SerializationThreadWorker.Exit() SerializationThreadWorker.cs:61
Server.World.ExitSerializationThreads() World.cs:429
Server.Tests.UOContentFixture..ctor()
```
### Root cause
Both collection fixtures (`UOContentFixture` and `PathfindingTestFixture`) each run the **full process-global ModernUO bootstrap**. `World.Load()` is guarded to run once per process, so the **second** fixture's `World.Load()` is a no-op and does **not** respawn the serialization workers — but `World.ExitSerializationThreads()` is **not** guarded, so the second fixture calls `Exit()` on workers whose threads have already terminated. `Exit()` → `Sleep()` → `_stopEvent.WaitOne()` then blocks forever (a dead thread never sets the event). The first collection's tests run; the second collection's fixture deadlocks in its constructor; the host eventually gets killed.
This is why single-collection (filtered) runs were fine — only one fixture ever bootstraps — but the full suite hangs. It's not a parallelization race: even strictly sequential, the second fixture deadlocks.
## Fix
**(a) Engine — idempotent `SerializationThreadWorker.Exit()`**
A second `Exit()` is now a safe no-op instead of a permanent block. Only the owning (main) thread calls `Exit()`, so no synchronization is needed, and the single-call production shutdown path is unchanged.
**(b) Tests — one shared bootstrap, strictly sequential collections**
- New `TestServerBootstrap.EnsureInitialized()` runs the superset global init **exactly once per process** (lock + once-flag).
- `UOContentFixture` / `PathfindingTestFixture` slim down to delegate to it and no longer tear down global state (which the single-bootstrap model owns for the host's lifetime).
- `[assembly: CollectionBehavior(DisableTestParallelization = true)]` so collections never overlap.
## Result
| | Before | After |
|---|---|---|
| Tests run (full suite) | 258 (UOContent collection deadlocked) | **418** |
| Outcome | 2.5-min hang → host crash | **418 passed, clean exit** |
| Wall time | killed | **~7s** |
## Summary
Fixes two related pet-behavior bugs and the underlying design flaw behind both:
1. **Post-combat erratic** — after a pet killed its `all kill` target it milled around erratically at the kill site (or failed to return to the master) until the player issued `all follow`/`all stop`.
2. **`all stop` returns home** — a pet with a non-zero `Home` walked back toward that location on `all stop` (on ML; on non-ML the old `DoOrderStop` was a no-op, so the sighting there came from a residual `Stay`).
### Root cause
`ControlOrder` and the wild-creature `Home` field were overloaded to express several distinct ideas, mutated/read inconsistently across order transitions:
- `Home` doubled as the controlled-pet "stay anchor" (`HandleStayOrder` set `Home = Location`) but nothing cleared it when the pet left the staying state; `HandleStopOrder` was the only handler that never touched it.
- `DoOrderStop` had dropped RunUO's `Home = Location` re-anchor, so on ML it walked to a stale anchor.
- The post-combat fallback was a fragile `_lastPetOrder` hack in `DoOrderNone` that re-anchored a resumed `Stay` at the corpse.
- Controlled idle-wander bypassed the `CheckIdle()` rest gate that every non-controlled creature uses, so idling pets jittered every AI tick.
## Approach
Separate three concepts that were tangled together:
- **`ControlOrder`** — the active order (may be transient: Come/Attack/Drop).
- **Persistent command** (`PersistentOrder` ∈ `{None, Stay, Follow, Guard}`) — the standing directive a pet falls back to when a transient order completes. Runtime-only (not serialized; reset to `None` on load) and **derived from master proximity on login** (near → Follow, far → Stay).
- **Anchor** (`Home`) — a pure function of the persistent command, set only when that command changes (never on transient transitions or fallback-resume), so it can't go stale.
### Behavior
- **Stop** is resolved immediately from what the pet was doing: Attack/Come → resume the persistent command; Follow/Guard → cancel to idle where it stands; Stay → stay put.
- **Stay** holds its post (returns only if displaced, e.g. after a fight) — no shuffle.
- **Idle** (`None`) is a gentle wander routed through `CheckMove/CanMoveNow/CheckIdle`, so idling pets take the same 15–25s rest periods as other creatures, on both ML and non-ML.
- **Post-combat** the pet resumes its persistent command (a staying pet returns to its original post, not the corpse).
- **Release** without a spawner anchors where the pet stands instead of pathing to a stale anchor.
This restores the RunUO-intended behavior (verified against the RunUO reference) while fixing the ModernUO regressions.
## Tests
New `PetOrderTests` (13 deterministic xUnit tests) cover: anchor lifecycle, the full Stop truth table, report 1 (post-combat return to post), report 2 (no stale-anchor walk-home), frozen-Stay/gated-idle wiring, release fix, derive-on-login, and a non-ML spot-check. The subjective wander *feel* is covered by a manual-QA checklist in the implementation plan.
## Notes
- Engine project (`Projects/Server`) untouched; the one `BaseCreature.cs` change is the `ControlOrder` setter passing the previous order to `OnCurrentOrderChanged`.
- `DoOrderCome` keeps auto-converting to `Stay` on arrival, which under the new model cleanly means "come and hold near me."
- Commits in this PR are temporarily **unsigned** (the signing agent's passphrase cache expired mid-session); happy to re-sign / amend on request.
## Summary
Phase #3b (final roadmap item), stacked on #2470. Compacts the index trailer from 20 to 8 bytes/chunk.
Trammel: 19.2 MB → 17.9 MB. Roadmap total: 565 MB → 17.9 MB (−96.8%).
## Details
- Trailer stores `{ u32 packedKey = (ChunkX << 16) | ChunkY, u32 recordLength }` per chunk, in record write order; the file offset is dropped and reconstructed by cumulative recordLength from HeaderSize.
- No record reordering, no varint; fixed-stride, TryReadChunk unchanged.
- Also simplifies the accumulated `.swb` code comments across the stack.
- Format v8; v7 files rejected and re-baked once.
## Tests
v8 multi-chunk round-trip (cumulative offset reconstruction) + the v6/v7 suite; full pathfinding suite green; Release build clean.
## Summary
Phase #3a, stacked on #2469. Compresses each chunk record independently with libdeflate (random access preserved).
Trammel: 124.7 MB → 19.2 MB (−85%).
## Details
- Whole-record framing `[u32 UncompressedLen][payload]`; records that don't shrink (tiny Uniform) are stored raw, detected as payload length == UncompressedLen.
- Codec chosen by full-Trammel spike: libdeflate VeryHigh (16.5 MB, 1.83 µs/chunk decompress) over zstd L19/22 (17.4 MB) and managed Brotli q11 (16.4 MB) — best native ratio, fastest decompress, already the repo's packet codec (no new dependency).
- Reuses cached thread-static bindings: `Deflate.Maximum` for bake, `Deflate.Standard` for reads.
- Compression is bake-time only; decompression is one-time per chunk (LRU-cached).
- Format v7; v6 files rejected and re-baked once.
## Tests
v7 unit tests + the v6 suite run through the compression path; full pathfinding suite green; Release build clean.
## Summary
Phase #2 of the `.swb` step-cache size-reduction roadmap (after #2465, v5 uniform elision). Stores the 16 base directional Z arrays as masked residuals against each cell's own SourceZ and omits any array that matches its prediction. Lossless, byte-identical reconstruction.
Trammel: 231.9 MB → 124.7 MB (−46%).
## Details
- Predictor: `predict = mask bit ? SourceZ : 0` (matches the baker's 0 on unwalkable directions); residual `Z − predict` via unchecked two's-complement (byte-exact for all inputs); reconstruct `Z = predict + residual`.
- A `u16 ZArrayMask` flags which of the 16 base arrays differ from prediction; matching arrays are omitted and synthesized from mask + SourceZ at read.
- Serializer-layer only: StepChunk, the cache, the algorithm, and the baker are unchanged.
- Format v6; v5 files rejected and re-baked once.
## Tests
21 v6 unit tests; full pathfinding suite green; Release build clean.
## Issue
Fixes#2452. A player with 30 Ninjitsu reported that the Animal Form menu showed **every** form; selecting one above their skill (e.g. Dog, req 40) **consumed mana** and returned "you need at least 40 skill", and afterwards the **gump never reopened** — every recast silently re-attempted the unusable form and drained more mana.
## Root cause
Three linked bugs, all reproduced from the code:
1. **Gump not gated by skill.** `AnimalFormGump.BuildLayout` compared `Skill.Fixed` (which is `Value * 10`, so 30 skill → `300`) against the raw 0–100 `ReqSkill` (Dog = `40`). `300 >= 40` is always true, so all forms were shown. `Morph` itself correctly uses `.Value`.
2. **Mana charged on a no-skill cast.** `Morph` returns `MorphResult.NoSkill` for an under-skilled form, but both call sites (`OnCast`, `OnResponse`) only special-cased `MorphResult.Fail`; `NoSkill` fell through to the branch that deducts mana.
3. **Menu never reopened.** Per OSI ([uo.com](https://uo.com/wiki/ultima-online-wiki/skills/ninjitsu/), [uoguide](https://www.uoguide.com/Animal_Form)), casting while **standing still always opens the selection menu**, and casting while **moving** quick-transforms into the last selected form. ModernUO only opened the menu when `lastAnimalForm == -1`, so once any form was selected a stationary recast skipped the menu.
## Fix
- Add `AnimalForm.CanSelectEntry` (compares `Skill.Value` to `ReqSkill`, plus the talisman check) and use it for the gump's per-entry enable check.
- `OnCast`: standing still always opens the menu; moving quick-transforms into the last form. `NoSkill` no longer costs mana.
- `OnResponse`: handle `Success` / `Fail` / `NoSkill` explicitly so `NoSkill` costs no mana.
## Tests
Adds `AnimalFormTests`:
- `CanSelectEntry` rejects forms above skill, accepts forms at/below skill, and requires a talisman for talisman-gated forms.
- `Morph` returns `NoSkill` (without transforming) when under-skilled, and `Success` when sufficiently skilled.
Verified the gating test catches the regression (reintroducing `.Fixed` fails it). Full solution build is clean; the 5 new tests plus 284 other UOContent tests pass (the pathfinding/AI sequential tests were excluded only because they deadlock under concurrent local runs — they are unrelated to this change).
## Summary
Sub-project #1 of the `.swb` step-cache size-reduction roadmap (`dev-docs/pathfinding.md` § Future work). Adds **uniform-chunk elision** to the `StepCacheFile` format, bumping it **v4 → v5**.
A fully-uniform 16×16 chunk — no strata, **no swim layer**, all 19 base arrays constant (open ocean, Green Acres, void) — serializes to a **~28-byte record** (`KindUniform`) instead of ~5,393, and reconstructs **byte-identically** via `Array.Fill`. Non-uniform chunks use the existing v4 body (`KindFull`) with the swim-layer and strata trailers **fully preserved** — the Kind byte is just prepended.
## Calibrated result (measured, not projected)
Baked Trammel via `SaveToFile`:
| | |
|---|---:|
| Chunks | 114,688 |
| Uniform (swim-aware) → elided | 62.7% |
| Swim-layer chunks (stay Full) | 8.9% |
| Strata chunks (stay Full) | 1.8% |
| Baseline (full records) | 592.2 MB |
| **Actual v5 `.swb`** | **231.9 MB (−61%)** |
The residual is ~150 MB of non-uniform land Z-blocks (targeted by #2 predictive-Z) + ~81 MB of swim-layer trailers (#2/#3). #2 and #3 are separate follow-up PRs.
## Implementation
- `StepChunk.IsUniform()` — false if it has strata **or a swim layer**, else true only when all 19 base arrays are constant (the "all-same" check uses the SIMD-accelerated `ContainsAnyExcept`).
- `StepCacheFile` v5 — `Kind` byte (`KindFull=0`/`KindUniform=2`, 1 reserved); uniform write/read; `FormatVersion`/`MinSupportedVersion` → 5 (v4 files rejected on open and re-baked). No `StepCache`/algorithm/index changes; fingerprint logic untouched.
## Tests
7 `StepCacheFileV5Tests` (uniform round-trip + `<200 B` compactness, varied-full, swim-layer-full, strata-full, swim+strata combined, v4 version-gate rejection) + the existing StepCache/pathfinding suite — **70 pass**, including the prior `SwimLayer_RoundTrips`. An independent review verified write/read symmetry, cast round-tripping, swim/strata preservation, and the version gate (READY TO MERGE).
Fixes#2462
## Summary
Removes the per-object `VirtualHairInfo` heap wrapper for mobile/corpse hair. Hair is now stored **inline** on `Mobile` and `Corpse` as `int _hairItemId` / `int _hairHue` plus a lazily-allocated, **non-serialized** ephemeral `Serial _hairSerial` (in the high virtual-serial range) — and likewise for facial hair. The `VirtualHairInfo` class is deleted, with a **lossless** save migration.
This delivers three things:
1. **Fixes a hair-removal bug.** `Delta(MobileDelta.Hair)` is deferred (it enqueues; `ProcessDeltaQueue` runs later in the tick). The old `HairItemID = 0` setter nulled `_hair` *immediately*, so by the time `ProcessDelta` built the remove packet the equipped virtual serial was already gone — the old `??=` code then re-materialized a **fresh** serial (≠ the equipped one), so clients never removed the right entity, and it left a phantom ItemId-0 object behind. The serial now lives on the entity and **persists across removal**, so remove packets carry the correct serial.
2. **Lightens the entity.** No heap hair object; bald mobiles allocate nothing (the serial is minted lazily only when hair is present). This was the original reason `HairItemID`/`HairHue` exist.
3. **Removes `VirtualHairInfo` entirely**, keeping the high-range virtual serial behavior.
## How
- **Mobile** (manual serialization): inline `_hairItemId/_hairHue/_hairSerial` (+facial); lazy `HairSerial`/`FacialHairSerial`; `ProcessDelta` reads those. Serialization **v36 → v37** — the v30-v37 deserialize is unified, reading the legacy per-hair `VirtualHairInfo` version int only when `version < 37`. Setting item id to 0 clears the hue (matching the old object-nulling) while retaining the serial.
- **Corpse** (codegen serialization): decomposed to `[SerializableField] int _hairItemId/_hairHue` (+facial) + ephemeral serial; **v16 → v17** with `MigrateFrom(V16Content)`.
- **Lossless migration:** the loader validates exact byte length, and the old corpse hair is a presence-bool-gated block, so a tiny **migration-only** `LegacyHairInfo` reader (no runtime role) consumes the legacy `[bool][int ver][int itemId][int hue]` bytes. Frozen `Corpse.v14/v15/v16.json` are retyped to it; `v17.json` describes the new int fields.
- All consumers updated to discrete accessors: `OutgoingMobilePackets`, `CorpsePackets`, corpse subclasses (`MilitiaFighterCorpse`, `SchmendrickApprenticeCorpse`), and the packet test mirrors.
- `VirtualHair.cs` renamed to `OutgoingVirtualHairPackets.cs` (the only type left in it after `VirtualHairInfo` was removed).
## Test Plan
- [x] Full solution build: **0 warnings, 0 errors** (`TreatWarningsAsErrors`).
- [x] `Server.Tests`: **708 passed** (incl. new `RemoveHairUsesEquippedSerial` / `RemoveFacialHairUsesEquippedSerial` proving the serial survives removal + hue clears).
- [x] `UOContent.Tests` corpse/hair: **6 passed** (incl. `CorpseHairMigrationTests` asserting the legacy hair bytes are consumed exactly — the loader's length invariant).
- [x] Generated migration code inspected: V14/V15/V16 readers consume the legacy block byte-for-byte; serial never written to disk.
## Upgrade notes
- Old Mobile (v30–v36) and Corpse (v13–v16) saves load losslessly.
- Minor cosmetic-only change: `SchmendrickApprenticeCorpse` hair/facial-hair RNG draws shift order within each pair (same draw count); irrelevant for a quest NPC corpse.
## Summary
Adds `dev-docs/pathfinding.md` — a reference for how creature pathfinding works in ModernUO, written so a future contributor (human or AI) can reason about it without re-deriving it from the code.
Covers:
- **The stack** end to end: `ApproachTarget` → `PathFollower` → `MovementPath` → `BitmapAStarAlgorithm` → `StepCache` → `MovementImpl` slow path (and that the removed FastAStar survives as the slow path).
- **Windowed-A* limits** (`AreaSize=38`, `MaxSearchNodes`, Z planes) and what they mean (2D-adjacent-but-obstacle-separated / a-floor-up goals are unsolvable by design).
- **StepCache**: second-touch warming, LRU-bounded memory, lazy `.swb` backing stores — with **measured** disk sizes (~565 MB/Trammel; ~1.5–2 GB all facets).
- **Four config levers** in a table: `pathfinding.enable`, `bitmap_pathfinding_cache`, `pathfinding.maxResidentChunks`, `pathfinding.maxSearchNodes`.
- **Small/crappy-hardware shard spectrum** (cache off ≈ FastAStar at ~1× with zero warming memory, up through baked `.swb`).
- **Diagnostics & tooling** (`[PathCacheStats`/`[PathRecord`/`[PathBake`, the MapDump tool, the benchmark suite) and the Debug/Release test note.
- **Future work**: background-thread bake, long-traverse BDN scenario, swim `SourceZ` bake, and the `.swb` size-reduction roadmap.
## Note on scope
This is docs-only. It documents the *complete* pathfinding system, so it references a couple of pieces that ride in separate PRs (the `ApproachTarget` AI fix and the `pathfinding.maxSearchNodes` setting). If those havent merged yet, sequence this after them so the doc doesnt describe unshipped code. The StepCache/`.swb`/provider material it documents is already on `main`.
## Summary
Closes the Cold-cache regression flagged in PR #2450. `StepCache.TryGetMask` no longer eagerly runs `BuildChunk` on the first miss for a chunk that isn't in a `.swb` lazy reader. Instead it returns `Fallthrough_NotBuilt` and the caller (`BitmapAStarAlgorithm`) takes the per-cell slow path. The chunk is only promoted to the bitmap fast path after the **second** miss within a 30-second window, filtering single-touch pass-throughs.
This makes BitmapAStar's worst-case (cold cache + short hops) collapse from **12–47× slower** than FastAStar to **roughly the same**, which is the floor the slow path can deliver. Steady-state warm performance (the actual deliverable) is unchanged from PR-5 — it was always the cache fast path.
## The pet-follow scenario this fixes
A mounted player at ~4 tiles/sec with a pet/hireable following will trigger an NPC pathfind every 100–300 ms. Each pathfind is 1–6 tiles. As the player crosses chunk boundaries (~4 sec/chunk), the pet's first pathfind in the new chunk under the previous behavior triggered a full ~700 µs `BuildChunk` for a chunk the player would leave shortly after. At 50–100 mobiles per shard, this exceeded the 8 ms tick budget. PR-5 BDN data showed scenarios 6–9 (2–8 tile NPC perception) at 2,300–3,700 µs Cold vs FastAStar's 80–200 µs.
Under the new gate:
- First miss → `Fallthrough_NotBuilt` → caller uses slow path (~30–50 µs short path). No `BuildChunk`. No allocation.
- Player keeps moving → chunk never gets a second touch within window → never promoted, no rot.
- NPC patrolling a fixed territory → repeatedly hits the same chunks → second touch within window → promote → cache fast path on subsequent calls.
## What changed
- **`CacheHitKind.Fallthrough_NotBuilt = 6`** + **`CacheStats.FallthroughNotBuilt`** counter. `IsHit=false`, so the caller routes to slow path.
- **`StepCache._chunkMissTracker`** — `Dictionary<long, ChunkMissState>` capped at 4096 entries. State is `(byte missCount, uint lastMissTickStamp)` keyed by chunk key. Window-expired entries reset count to 1; capacity overflow prunes window-old entries first.
- **`StepCache.MissPromotionThreshold`** (default `2`) and **`StepCache.MissPromotionWindowMs`** (default `30_000`) — tunable, can be wired through `ServerConfiguration` if shards want different policy. Setting threshold to `1` restores legacy eager-build behavior (used by tests that prime chunks via single `TryGetMask` call).
- **`StepCache.TryGetMask` miss branch** — try lazy reader first (file-loaded chunks bypass the tracker entirely; an `.swb` represents an explicit prior decision to keep the chunk warm). Otherwise consult the tracker.
- **`BitmapAStarAlgorithm.GetSuccessorsSlowPath`** now layers `IsBlockedByDynamic` on top of `CalcMoves.CheckMovement`. Previously the slow path only ran for `CanFly` creatures and rare cache fallthroughs — `CheckMovement` doesn't iterate same-cell mobiles, so the bitmap fast path's `IsBlockedByDynamic` was the only mobile-blocking check. Now first-touch pathfinds run through the slow path, so the gap had to close.
## Tests
50 pathfinding tests pass (was 47). New / updated:
- **`TryGetMask_FirstTouchOnUnbuiltChunk_DefersBuildAndReturnsFallthrough`** — single TryGetMask call returns `Fallthrough_NotBuilt`, no chunk built, no allocation.
- **`TryGetMask_SecondTouchWithinWindow_PromotesAndBuilds`** — second call inside the 30s window builds + serves.
- **`TryGetMask_SecondTouchAfterWindow_RestartsCounterAndDefers`** — second call outside the window restarts the count, returns Fallthrough again.
- **`TryGetMask_DistinctChunks_TrackedIndependently`** — counters are per-chunk; one touch on each of two adjacent chunks both stay in fallthrough.
- **`LazyReaderHit_BypassesMissTrackerOnFirstTouch`** — open `.swb` + first touch hits without consulting the tracker. Production with `.swb` loaded skips the gate entirely.
- **`MultisVersion_Bump_TriggersDirtyRebuild`** — updated to reflect the new 3-step flow (Fallthrough → Miss_NotBuilt → Miss_DirtyRebuild).
- Tests that prime chunks via a single `TryGetMask` call (multi-Z, Tier4, lifecycle, parity, BitmapAStar uses-cache) set `MissPromotionThreshold = 1` to opt into eager behavior.
## Expected BDN impact
The Cold column from PR-5's BDN should change as follows once the bench's submodule pointer is updated to this branch:
| # | Scenario | Cold (PR-5) | Cold (PR-6 expected) | FastAStar Cold |
|--:|-----------------|-------------:|---------------------:|---------------:|
| 2 | sewer corridor | 1,627 µs | ~36 µs | 36 µs |
| 4 | causeway | 1,533 µs | ~39 µs | 39 µs |
| 6 | pet 2-tile | 2,364 µs | ~80 µs | 81 µs |
| 8 | npc 5-tile | 3,708 µs | ~140 µs | 141 µs |
| 9 | npc 8-tile | 2,386 µs | ~200 µs | 197 µs |
WarmNoFile and LazyWarm rows should be unchanged — they were always cache-warm. The miss tracker only fires when neither resident chunks nor the lazy reader can satisfy the request.
## Future work (not in this PR)
- **Background-thread bake**: builds outside the game thread so even promoted chunks don't pay the 700 µs build cost on the main thread. Rule 10 (no Task.Run) applies, so this needs careful design — the bake is a pure data transform but main-thread synchronization on chunk-state transitions has to be threaded through. Defer to a follow-up.
- **Long-traverse BDN scenario**: a multi-Find benchmark simulating 50 pet repaths across chunk transitions. Requires restructuring the bench harness; the existing 10-scenario corpus + Cold provider already exercises the gate.
- **Swim sourceZ bake**: scenario 5 (sea serpent) shows 56 B alloc on warm paths because the cache's SourceZ is computed under default-walker rules. Swim creatures fall through to slow path. Independent of this PR.
## Summary
Creatures (pets following, monsters chasing, NPCs approaching) would **oscillate — "pace back and forth really fast"** at concave obstacles (reported at the Britain Inn L-desk: a pet at `(1493,1614,20)` never reaching its master at `(1494,1605,21)`) instead of routing around them.
**Root cause** (the A* pathfinder itself was correct): all goal-seeking funnels through `MoveTo` and `WalkMobileRange` → `MoveTowardsOrAwayFrom`, which step greedily via `DoMove(dir, badStateOk:true)`. `DoMove` returns `true` even when the direct step was blocked and the creature merely **auto-turned and sidestepped** (`MoveResult.SuccessAutoTurn`), and the caller then set `Path = null`, discarding the `PathFollower`. So at a concave obstacle a non-progressing sidestep was mistaken for progress and the creature never committed to a route. (AOS pet-follow runs at `CurrentSpeed = 0.1`, hence the "really fast" shuffle.)
## What changed
- **New centralized `BaseAI.ApproachTarget(target, run, range)` primitive.** A greedy step is committed only when it **fully succeeds (`MoveResult.Success`) and actually gets closer**; otherwise the creature commits to a **persistent `PathFollower`** that routes around the obstacle and is never discarded by a greedy step. The open-terrain fast path (one greedy step, no pathfinding) is preserved. `MoveTo`, `MoveTowardsOrAwayFrom`, and `MoveToWithCollisionAvoidance` all delegate to it — public signatures unchanged, so no AI-class call site changes.
- **Best-distance give-up + idle.** A creature that cannot reach a **stationary** in-range goal stops shuffling and idles after `ApproachGiveUpTicks` (40) ticks without lowering its closest-ever distance; a **moving** goal (active chase) never gives up. It resumes the moment the goal moves.
- **Pathfinder fix (required):** `BitmapAStarAlgorithm.IsBlockedByDynamic` now skips the dynamic mobile-block check **at the goal cell only** (`MoveImpl.Goal`). Previously A* returned `null` whenever the target mobile stood on the goal cell, so creatures could never pathfind *toward* another mobile — only toward empty ground. The follower stops within `range` short of it. Static/item blocking and all non-goal mobile blocking are unchanged.
## Tests
New AI-loop integration tests in `ApproachTargetTests.cs` drive the real `BaseAI` primitives against live Britain Inn map statics: exact-repro pet follow, open-terrain (asserts zero pathfinding), `MoveTo` chase (static + walking-away target), route-around-a-dynamic-wall, and walled-off give-up-and-idle.
- Pathfinding + AI subset: **52/52** pass.
- Full `UOContent.Tests`: **301/301** pass. (Note: the test host lingers on shutdown — a pre-existing infra quirk unrelated to this change; all tests complete and pass.)
- Full solution build: clean (0 warnings / 0 errors).
## Notes
- Branched off `main`; independent of the in-flight step-cache work.
- Out of scope (future work): proactive "SmartAI" look-ahead pathfinding so clever creatures plan a route before walking into the obstacle, rather than reacting after they hit it.
## Test Plan
- [X] In-game: order a pet to `follow`/`come` across the Britain Inn L-desk; confirm it routes around and reaches you instead of pacing.
- [X] Aggro a monster and kite it around a building/treeline; confirm it chases around obstacles.
- [X] Confirm open-terrain following/chasing feels unchanged (no extra latency).
- [X] Confirm a creature with a genuinely unreachable target idles rather than shuffling forever.
## Summary
Multi-Z cells (bridges, stairs, paver-over-ground, multi-floor structures) now carry **per-stratum walkability data** in the cache instead of falling through to the slow path. The data is computed at chunk-build time, persisted in the `.swb` file, and selected at query time by matching the request's `sourceZ` against each stratum's `zCenter` (within `StepHeight` tolerance).
This is the Tier 4 strata feature, deferred from PR #2447 / PR #2448 / PR #2449. Builds on PR #2449's lazy backing store and public bake helpers.
## Wire format change (v1 → v2)
`StepCacheFile.FormatVersion = 2`. `MinSupportedVersion = 2`. v1 `.swb` files are silently rejected at open time (treated as missing) and overwritten on the next `SaveToFile` / `BakeMap`. **No migration** — older files just get re-baked.
The `MinSupportedVersion` sentinel is the model going forward: bump the constant when an incompatible change lands; admins re-bake on the next deploy. No matrix of v1↔v2↔v3 migration logic to maintain.
## What changed
- **`StepProbe.ComputeStrataAt(map, x, y)`** — enumerates walkable standing-Zs at the cell (one per land surface plus one per walkable static), collapses Zs within `2*StepHeight`, runs `ComputeMaskAt` at each surviving Z. Returns `null` for single-Z cells (caller uses the chunk's main mask).
- **`StepChunk`** — replaces the old `MultiZCells` bitmap with a **strata storage pair**:
- `ushort[256] StrataOffsetByCell` (sentinel `NoStrata = 0xFFFF` = "no strata for that cell")
- `byte[] StrataData` packed: `u8 stratumCount`, then `count × 19-byte stratum`
- `sbyte zCenter, byte walkMask, byte wetMask, sbyte walkZ_N..NW (8), sbyte swimZ_N..NW (8)`
- `IsCellMultiZ` derives from `StrataOffsetByCell[cell] != NoStrata` — same semantics, single source of truth.
- **`StepCache.BuildChunk`** — populates strata for cells flagged multi-Z via `SetStrata`. Chunks with zero multi-Z cells pay zero strata overhead (offset array + data array stay null).
- **`StepCache.TryGetMask`** — for multi-Z cells, scans strata with `TryStratumHit`; returns the matching one with `HitKind=Hit`. Falls through to slow path only when no stratum matches the query `sourceZ`.
- **`StepCacheFile`** — v2 serialization with strata trailer per chunk + `recordLength` in index entry. Lazy reader sizes scratch per-chunk-record using the recorded length, growing on demand for multi-Z-heavy chunks. Patches `IndexOffset` on `w.Buffer` (BufferWriter's current backing array) since it grows during variable-size chunk writes.
## File layout v2
```
Header (48 bytes):
u32 Magic = 0x42575300 ('SWB\0')
u32 Version = 2
u32 MapId
u64 Fingerprint XxHash3 over LandTable + ItemTable flags + map files (mapX.mul/.uop, staidxX.mul, staticsX.mul)
u64 BakeTimestamp informational
u32 ChunkCount
u64 IndexOffset position where chunk index begins
Per chunk (variable size):
u16 ChunkX, ChunkY
u32 BuiltMultisVersion
u8 HasStrata 0 = no strata trailer; 1 = strata trailer follows
byte WalkMask[256], WetMask[256]
sbyte SourceZ[256], WalkZN..WalkZNW[256], SwimZN..SwimZNW[256]
// Strata trailer (only when HasStrata == 1):
u16 StrataOffsetByCell[256] // NoStrata sentinel = 0xFFFF
u32 StrataDataLength
byte StrataData[StrataDataLength]
Per multi-Z cell: u8 count, then count × Stratum (19 bytes)
Index trailer (20 × ChunkCount bytes):
per chunk: { u64 chunkKey, u64 fileOffset, u32 recordLength }
```
## Summary
Adds two pieces of pathfinding tooling on top of PR #2448's lazy `.swb` infrastructure:
- **`PathfindRecorder`** — admin-toggled JSONL telemetry capture; one record per `BitmapAStarAlgorithm.Find` call. Output format matches the BDN harness corpus, so production traffic can be captured and replayed in benchmarks without an adapter.
- **Public bake helpers on `StepCache`** — `ComputeLiveTileDataHash`, `TryReadTileDataHashFromFile`, `BakeMap`, `ClearResidentChunks`. Lets the benchmark project (and any future bake utility) drive cache fill + persist without exposing internal types.
The companion BDN harness update lives in [ModernUO-Benchmarks#kb/pathfinding-pr4-bench](https://github.com/modernuo/ModernUO-Benchmarks/tree/kb/pathfinding-pr4-bench): porting `Benchmarks/PathfindInGame/` from the `kb/ai_pathfinding` branch to the API shipped in #2446–#2448.
## What's in this PR
### `PathfindRecorder` (`PathfindRecorder.cs`)
- Holds a single `StreamWriter` open while recording; its internal buffer absorbs per-record writes without per-call `File.AppendAllText`.
- Single `bool` check on the hot path; cheap when disabled.
- Disabling flushes + disposes; an IO failure during write also disables the recorder.
- Server config:
- `pathfinding.recorder.enable` — bool, default `false`. Read on boot via `GetOrUpdateSetting`.
- `pathfinding.recorder.path` — default `<basedir>/Data/Pathfinding/recordings/pathfinds.jsonl`.
- Hooked into `BitmapAStarAlgorithm.Find` — runs once per call, does nothing when disabled.
- Admin command: `[PathRecord [on|off|flush|status]` (default `status`).
### Public cache helpers
- `static ulong StepCache.ComputeLiveTileDataHash()` — wraps the file module's hash function for staleness checks.
- `static bool StepCache.TryReadTileDataHashFromFile(string, out ulong)` — peeks at a `.swb` file's hash field (20 bytes).
- `int StepCache.BakeMap(int, string)` — walks every chunk in the map, populates resident set, saves. Offline / fixture use; blocks for many seconds on a full-map walk.
- `void StepCache.ClearResidentChunks()` — drops chunks + zeros counters but keeps lazy readers open. Lets benchmark loops measure "first query after boot" cost across iterations without the lazy-reader reopen overhead.
## Summary
Adds a binary disk format + lazy reader so the step cache can warm-start from a precomputed file without paying chunk-build cost on the first pathfind through a region. **Resident memory stays bounded by `MaxResidentChunks` regardless of file size** — opening a `.swb` reads only the header + chunk-offset index (~16 bytes per indexed chunk), and individual chunks are seeked + deserialized only when `ResolveMissingChunk` asks for them.
The lazy design (vs. an eager bulk load): a 250 MB bake on a RAM-constrained shard never materializes more than the LRU cap (~40 MB at the default 8192-chunk cap), and unwanted regions never enter memory at all.
Builds on PR #2447.
## What changed
- **`StepCacheFile`** — binary reader/writer module. Writer emits header → chunks (offsets recorded) → index trailer, then patches the header's `IndexOffset` field. Reader is `OpenForLazy(path)` returning a `LazyReader` that holds an open `FileStream` + offset dictionary.
- **`StepCacheFile.LazyReader`** — `TryReadChunk(chunkX, chunkY)` does a single seek + bulk read for one record. `Dispose` releases the underlying stream. Files are opened with `FileShare.Read | FileShare.Delete` so admin tooling can replace them.
- **TileData fingerprint via XxHash3.** The `.swb` header carries a hash of `LandTable + ItemTable` flags. Load rejects any file whose hash doesn't match the running server. Computed via `HashUtility.ComputeHash64` (engine-blessed hasher) — adds a `ReadOnlySpan<byte>` overload alongside the existing `ReadOnlySpan<char>` one for parity.
- **`StepCache.SaveToFile(path, mapId)`** — writes resident chunks for the given map.
- **`StepCache.TryOpenLazyReader(path, mapId)`** — opens the file, validates header, holds the reader for the map's lifetime.
- **`StepCache.ResolveMissingChunk`** — now consults the lazy reader before invoking the runtime baker. A loaded chunk whose `BuiltMultisVersion` doesn't match the live sector falls through to the baker (snapshot was made before a multi was added/removed in that sector).
- **`StepCache.Clear` closes lazy readers.** Test cleanup can delete `.swb` files cleanly.
- **Auto-load at startup.** `PathCacheCommands.Configure()` opens `Data/Pathfinding/<mapId>.swb` as a lazy reader for every map.
- **`[PathCacheSave`** / **`[PathCacheLoad`** — admin commands for the same workflow.
- **`pathfinding.maxResidentChunks` shard-tunable.** Read from `server.cfg` at boot via `ServerConfiguration.GetOrUpdateSetting` (default 8192 ≈ 40 MB). Small shards can tune down; large shards with substantial bakes can tune up to reduce eviction churn. Default is written back to `server.cfg` on first boot, matching the engine pattern used by other settings.
## File layout (v1)
```
Header (48 bytes):
u32 Magic = 0x42575300 ('SWB\0')
u32 Version = 1
u32 MapId
u64 TileDataHash XxHash3 over LandTable + ItemTable flags (HashUtility)
u64 BakeTimestamp informational
u32 ChunkCount
u64 IndexOffset file position where the chunk index begins
Chunk records (fixed size, ~5,393 bytes each, +32 if multi-Z):
u16 ChunkX
u16 ChunkY
u32 BuiltMultisVersion
u8 HasMultiZ
byte WalkMask[256], WetMask[256]
sbyte SourceZ[256], WalkZN..WalkZNW[256], SwimZN..SwimZNW[256]
[byte MultiZCells[32] when HasMultiZ == 1]
Index trailer (16 × ChunkCount bytes):
(u64 chunkKey, u64 fileOffset)
```
## Memory math
| Scenario | Disk file | RAM at boot | Notes |
|---|---|---|---|
| Empty / no `.swb` files | — | 0 | Silent; cache builds on demand. |
| Admin-curated towns (5K chunks) | 25 MB | 0 + per-query | Index ≈ 80 KB. Resident grows to the configured cap under steady-state queries. |
| Full-map bake (50K chunks) | 250 MB | 0 + per-query | Index ≈ 800 KB. Same configured cap. Cold areas never load. |
| All 5 maps fully baked | 1.25 GB | 0 + per-query | Index ≈ 4 MB total. Same configured cap. |
## Hash choice (FNV-1a → XxHash3)
The original draft used inlined FNV-1a-64. Switched to XxHash3 via `HashUtility`:
- ~30× faster on this workload (~30 GB/s SIMD vs ~2 GB/s byte-by-byte). Boot-time only, so absolute saving is microseconds — the real wins are elsewhere.
- Stronger collision resistance and distribution.
- Drops ~25 lines of inlined hash code; matches the rest of the codebase's hashing pattern.
- Hash is stable as long as `HashUtility`'s `xxHash3Seed` constant doesn't change (already marked `// DO NOT CHANGE THIS NUMBER`).
## Summary
Builds on PR #2446's cache-direct A*. The previous PR conservatively routed players + creatures with capability flags entirely through the slow path. This PR pushes that line: most mobile classes now use the cache, with the right rule set layered on top per-mobile, and the cache fast-path now does the dynamic items / mobiles check that PR #2446 had silently skipped.
## What changed
- **Non-GM players** now use the cache. Diagonal corner-cut applies the strict AND-rule (BOTH cardinal partners walkable) by reading the same source-cell mask byte the creature OR-rule reads — both rules are evaluable from one byte.
- **Creatures with `CanOpenDoors` / `CanMoveOverObstacles`** now use the cache. Reading `MovementImpl` confirmed those flags only affect dynamic items, never static tiles, so they were over-conservatively excluded before.
- **Swim creatures** now use the cache via a capability overlay. `StepProbe` bakes a second rule set (`canSwim=true, cantWalk=true`) producing `WetMask` + `SwimZ_*`. The algorithm composes `effectiveMask = (walkMask & !cantWalk) | (wetMask & canSwim)` per direction; walk Z preferred when both apply.
- **Dynamic-obstacle pass.** Cache fast-path now mirrors `MovementImpl`'s per-cell items + mobiles collision check (`GetItemsAt` / `GetMobilesAt` at the target cell, with `CanOpenDoors` / `CanMoveOverObstacles` / spell-field overrides). This closes a correctness gap from PR #2446 — the cache fast-path was silently skipping dynamic obstacles entirely.
- **`StepCache.TryGetMask` returns `StepMask` struct** instead of 11 out parameters. `HitKind` rolls into the struct with an `IsHit` accessor. Sets up wet/swim without ballooning the call site.
- **`StepChunk.MultiZCells` is lazy-init.** Most chunks are entirely single-Z; allocating the 32-byte bitmap up-front wasted ~256KB at full cap.
- **Admin commands.** `[PathCacheStats` (resident chunks + hit/miss/eviction counters) and `[PathCacheClear` (drop everything, zero counters).
- **Feature flag.** `bitmap_pathfinding_cache` (default true) gates the cache fast-path. Flipped off, every cell expansion routes to `MovementImpl` — equivalent to PR #2446's slow-path-only behavior. Safety net for shipping the new behavior.
`RequiresSlowPath` shrinks to just `CanFly` — flying creatures Z-jump arbitrarily, which the cache's static-Z model can't accommodate.
