Follow-up to #2721. It fixes how the remaining tests behave and changes no production code.
## CI
- Both `dotnet test` steps pass `--filter "Category!=Manual"`. Before this, Manual-tagged tests ran on CI anyway.
- The one surviving movement-throttle latency test is the only coverage of burst forgiveness over a full, wrapped history. It loses its Manual tag, so it runs on CI.
## Tests that passed on CI without testing anything
- **Corpse and throwing tests.** They relied on tiledata for the weapon `Layer`, so on CI the equip silently failed and they asserted against empty lists. They now set `Layer` explicitly and assert the equip took effect. `TestThrown` also pins its own strength and range values, so a shard retuning SoulGlaive no longer breaks them.
- **Healthbar poison rows.** Server.Tests registers no poisons, so every row tested `null`. They now use real poison levels.
- **Account packet tests.** The mock accounts reported `Length` 0, so the character-list tests only ever encoded empty slots. They now encode the real characters.
- **Pathing and AI tests that only mean something on real Trammel/Felucca terrain** are now guarded with `TileDataRequirement.SkipIfMissing()`: Britain desk and clutter scenes, house footprints (no MultiData on CI) and fingerprints. Tests that are valid on flat blank terrain stay unguarded. (A synthetic tiledata fixture to run these on CI is a planned follow-up.)
- **Assertions that couldn't fail now check their claim.** Affected tests include the `DefaultWalker` cache use, cache on/off parity requiring a path, the recorder capability flags, the idle-pet gate, the monthly DST recurrence, the AdvancedSearch `Record.Exception` wrappers, `CanFitItem` with no branch-guarded assert, the Firewall callback, and `Import_NoMap`. The Geometry Parse asserts also now use the same input as their TryParse.
## Shared state
Every test that changes process-wide state now restores it, even when an assert fails:
- **The clock.** A new `TimerWheelScope` saves and restores `Core._tickCount`, `Core._now` and the timer wheel. `SimulatedClockScope` covers decay tests.
- **StepCache settings and caches**, via `StepCacheStateScope`.
- **Network state.** The ManualAllowlist, LoginAllowlist, firewall and BanChannel reporters are restored. Global packet handlers are now registered per test and removed afterwards, so they no longer stay registered for later tests.
- **Data and config tables.** `ArchiveJournal` statics, `TileData.ItemTable`, `ObjectPropertyList.Enabled`, `Core.Expansion` and the localization table are restored. One `MobileStatusVersion` restore was resetting a different expansion than the one the test changed.
- **Entities.** Tests with fixed serials now delete what they create. Fixed mobile serials moved to `World.NewMobile`, because deleting a hard-coded serial could unregister a live entity.
- **Collection race.** `SpiralScanTests` no longer clears the spawn cache from a separate collection that could run in parallel with the cache-manager tests.
- **Shared statics.** Classes reading shared static allowlists joined the sequential collection.
## Duplication
New shared helpers replace copy-pasted harness code:
- **Server.Tests:** `PacketAssert.Sends`, used by about 130 packet tests; `TestClientHarness`, `PersistencePipelineScope`, `NetTestHelpers`, `EntityCleanup` and one `TestMulti`.
- **UOContent.Tests:** `TimerWheelScope`, which also holds one wraparound-safe `RunFor`/`RunUntil`; `AiTestStubs`, which merges six walker copies and five identical creature stubs; `MobileTestHarness`, `CommandTestHarness` and `TempDirectory`.
Dead oracle packet classes are removed.
## Cost
| Test | Before | After |
|---|---|---|
| `VirtualSerialTests` | 1.57s | 2ms (starts near the wrap via reflection instead of drawing ~17.9M serials) |
| Event scheduler recurrence loop | 473ms | 1ms |
| CrowdSec drain | 517ms | 16ms (event-driven instead of a fixed 500ms wait) |
| AuthId tests | 248ms | 99ms (SHA2 except the two GameLogin tests) |
| Container cap tests | 5,000 items | 3,449 / 3,277 (one past each protocol cap) |
| Bulk removal | 100k children | 20k children |
| OPL hash distribution | 60k builds | 10k builds |
## Shard-tuning decoupling
- AI assertions read `ReacquireDelay` and `FollowMoveSpeed` instead of hard-coding production tuning.
- The guard friendly-fire test uses an `AI_Mage` stub instead of WhiteWyrm.
- Argon2 assertions pin the `argon2id` variant and `v=19` but read the cost parameters from the configured hasher.
## Tests
| Run | Server.Tests | UOContent.Tests |
|---|---|---|
| With client files | 812 pass | 1,123 pass |
| Without client files (CI simulation) | 800 pass, 12 skip | 1,021 pass, 102 skip |
- The UOContent fixture reads `MODERNUO_TEST_DATA_DIR`; Server.Tests reads `MODERNUO_CLIENT_PATH`.
- The 15 new UOContent skips are the map-dependent guards above.
- Total run time with client files is about 5s, down from about 8s.
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
* Added World.NewVirtual for creating virtual serial numbers
* Reserved range 0x7EEEEEEE to 0x7FFFFFFF for virtual serials
* Hair and Facial hair (for mobiles) now use virtual serials instead of FakeSerial() functions
* Consolidated virtual hair to a single `VirtualHairInfo` class.
Corpse hair and facial hair now persists across save/load and hair and facial hair no longer teleport to newest corpse.
