## Problem
Every map's `.swb` step cache was opened, indexed and logged **twice** on boot.
`MovementPath.Configure()` explicitly called `PathCacheCommands.Configure()` and `CacheEvictionTimer.Configure()`. Both are types exposing a public static parameterless `Configure()`, which `AssemblyHandler.Invoke("Configure")` already discovers and calls once each (`AssemblyHandler.cs:157`). So `PathCacheCommands.Configure()` ran twice, and `AutoLoadAtStartup()` with it. `PathCacheCommands.Configure()` called `PathfindRecorder.Configure()` the same way.
`TryOpenLazyReader` disposes the prior reader before replacing it, so there was no handle leak — but the header and full chunk index of each `.swb` were read twice (~48 MB of files across six facets). The expensive `.mul` hashing was already memoized, so it was not doubled.
## Fix
Consolidate the cache lifecycle into `Initialize`:
- `Configure()` keeps only settings and command registration.
- `Initialize()` opens the readers once, then prebakes only maps that still lack one.
- The post-bake reopen is per-map instead of a blanket `AutoLoadAtStartup()` — on a partial bake (some valid `.swb`, one stale) that would close and reopen the readers already open, a second double-open on a different path.
`Initialize` is the correct phase. `Configure` runs before `TileMatrixLoader.LoadTileMatrix()` and `World.Load()` (`Main.cs:458/460/463/465`), so opening a `.swb` there forced the lazy `Map.Tiles` property — the fingerprint hashes the map files — and built every `TileMatrix` ahead of the loader that owns it, possibly before `TileMatrix.Configure()` settled `Pre6000ClientSupport`. Both sit at the default call priority and the phase sort is unstable. Moving pathfinding out leaves nothing in `Configure` that touches `Map.Tiles`, closing that hazard; the other 22 `.Tiles` users in UOContent are all runtime paths.
Multis stay out of the bake by design — houses and boats are player data that moves, handled by the multi-aware path at query time.
## Logging
The per-map `StepCache: opened ... chunks indexed` line drops to `Debug`. Opening is the expected case; `BakeMap` already logs a rebuild at `Information`, and `Initialize` still emits `PathBake: pre-bake complete (N map(s) written)`.
## Verification
- `dotnet build Projects/UOContent` — 0 errors, 0 warnings.
- `dotnet test --filter FullyQualifiedName~Pathfinding` — **123 passed, 0 failed**.
Boot logs should now show one `opened` line per map at `Debug`, none at `Information`.
## 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
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.
## Summary
Replaces `FastAStarAlgorithm` with `BitmapAStarAlgorithm`: one cache lookup per cell expansion (8-direction mask + per-direction destination Z) instead of 8 separate `MovementImpl.CheckMovement` calls. Adds the supporting cache infrastructure to back it.
Public API unchanged — `MovementPath` / `Mobile.Move` / `CalcMoves.Find` return the same shapes; the algorithm swap is internal.
## What's in this PR
- **`BitmapAStarAlgorithm`** — A* that issues one `StepCache.TryGetMask` call per cell expansion. Inline fallthrough to the per-cell slow path for multi-Z, off-map, source-Z mismatch, and non-default walkers.
- **`StepCache`** — singleton chunk store keyed by `(mapId, chunkX, chunkY)`. Lazily built on first query, invalidated by `Sector.MultisVersion` mismatch, memory-bounded by sampled probabilistic LRU.
- **`StepProbe`** — computes static-only walkability for a single cell, mirroring `MovementImpl.Check` minus the item / mobile collision phases.
- **`StepMask` / `StepChunk`** — value / storage types for the per-cell results.
- **`CacheEvictionTimer`** — periodic cap backstop (60s interval; early-returns when not over cap).
- **`Map.Sector.MultisVersion`** promoted to `public` so the cache can detect dynamic-static invalidations cheaply.
## Eviction strategy
Sampled probabilistic LRU (Redis-style). Per eviction, sample 5 random keys from a parallel `List<long>` kept in lockstep with the chunk dictionary; evict the oldest of the sample via swap-and-pop. O(1) per eviction regardless of resident count, so sustained cap pressure has no perpetual perf hit.
## Capability handling (interim)
Non-default walkers (non-GM players, creatures with `CanSwim` / `CanFly` / `CanOpenDoors` / `CanMoveOverObstacles`) route entirely through the per-cell slow path via `BitmapAStarAlgorithm.GetSuccessorsSlowPath`. The 2-pass design (cache + capability overlay + dynamic-obstacle pass) lands in the follow-up PR.
### Summary
- Fixes `[AdvancedSearch` being accessible by players 😱
- Adds `[GenCommands` to generate the same commands html page on https://muo.gg/commands.
- Fixes `[helpinfo` so all commands properly show up!
> [!WARNING]
> ### Developer Warning:
> Commands must now be registered in the `Configure` bootup phase.
> If a command is not registered early enough, it may not be available to systems like [helpinfo
> that cache their information.
> [!NOTE]
> ### Developer Note:
> Various commands related to generating content have been changed to _Developer_ and above access level.
### Screenshots
<img width="673" alt="image" src="https://github.com/modernuo/ModernUO/assets/3953314/b105b5c9-5eb4-4ace-93ff-1bfb31e7132f">
<img width="547" alt="image" src="https://github.com/modernuo/ModernUO/assets/3953314/e97487e8-47a5-4aa7-89cc-9fe3deda584d">
