## Why
Delta world saves re-serialize an entity only when it has been marked dirty. An audit of the generated classes found three ways serialized state changes without a mark; this PR closes the ones that do not need a new generator package.
## What
- **Custom `[SerializableProperty]` setters mark dirty.** Twelve hand-written setters assigned their backing field without `this.MarkDirty()`. `PlagueBeastLord.OpenedBy` was an auto-property carrying the attribute with no backing field at all; it is now a generated field with the same name, order and command-property exposure.
- **Generated sub-objects are linked to their owner.** Without a `[DirtyTrackingEntity]` member the generator emits setters that mark nothing. Eight entity-owned sub-objects now carry the link and receive the owner through the constructor the generator calls: `BOBFilter` (owner is `IEntity`: a `PlayerMobile` or a `BulkOrderBook`), `BOBLargeSubEntry`, `PuzzleChestSolution` and `PuzzleChestSolutionAndTime`, `TalismanAttribute` (the random factories now take the talisman), `VendorItem`, `PlayerBBMessage`, `RaffleEntry`, `ShardPollOption`. Migration schemas were regenerated with the pinned tool; the only change is the value rule argument becoming `DeserializationRequiresParent`.
- **BaseVendor uses the generator; restock amounts are no longer persisted.** The only state it wrote was which buy entries had grown restock amounts, packed by index into the live `SBInfos` tables. Restock is transient now and rebuilds on load; version 1 records are read and discarded through the legacy path. Every vendor subclass now serializes through a generated chain.
## Generator 4.1.0
This PR adopts SerializationGenerator 4.1.0 (modernuo/SerializationGenerator#55): SG3019/SG3020 diagnostics, `[VolatileSerializedState]`, `StopXxx()` timer helpers, and owner-constructor preference for sub-objects (so dictionary values are constructed with their owner; the 4.0.0 relink fallback is gone). `PlayerVendor.v3.json` gains `DeserializationRequiresParent` for its `VendorItem` values so the migration content struct constructs them with their vendor.
SG3019 is an error under `TreatWarningsAsErrors` and generator diagnostics ignore pragmas, so the five contexts that live in whole-file player-keyed persistences (`ChampionTitle`, `ChampionTitleContext`, `MurderContext`, `VirtueContext`, `JailRecord`) now carry a `[DirtyTrackingEntity]` link to their `PlayerMobile`, which is where they will live once those blobs move onto the player record. `JailSystem.EmptyRecord` keeps a null player (`[CanBeNull]`). `ChampionTitle` needs both a context and a player constructor because the generator resolves the rule against the containing type but emits the call with the parent field; a comment in the file records this.
## Wire format
Unchanged. No version bumps except `BaseVendor` 1 to 2 (which now writes nothing of its own). Schema diffs are rule-argument only (`DeserializationRequiresParent`).
## Testing
Server.Tests 848 passed, UOContent.Tests 759 passed.
## Summary
Folds **113** hand-written `[SerializableProperty]` members into plain `[SerializableField]` declarations using the v4 setter hooks — value coercion/vetoes via `allowFieldChange`, post-change side effects via `fieldChanged` (whose `oldValue` parameter covers the old-house/old-sender unsubscribe patterns). Net **-450 lines** of setter boilerplate.
```cs
// before
[SerializableProperty(1)]
[CommandProperty(AccessLevel.GameMaster)]
public int Charges
{
get => _charges;
set
{
_charges = Math.Clamp(value, 0, MaxCharges);
InvalidateProperties();
this.MarkDirty();
}
}
// after
[SerializableField(1, allowFieldChange: nameof(AllowChargesChange))]
[SerializedCommandProperty(AccessLevel.GameMaster)]
[InvalidateProperties]
private int _charges;
private bool AllowChargesChange(ref int value)
{
value = Math.Clamp(value, 0, MaxCharges);
return true;
}
```
## How sites were selected
A classifier parsed all 204 `[SerializableProperty]` sites and converted only those matching strict shapes: getter is exactly `get => _field;`, the assignment comes first (after at most an equality guard), and relocated side effects contain no `return`, no `value` mutation, and no field re-assignment. Everything else was left alone deliberately:
- **~34 custom getters** (fallback defaults like `_x == -1 ? Default : _x`, self-healing refs) — no setter hook can express these.
- **~35 pre-assignment logic** (durability Unscale/Scale sandwiches, old-state captures like PotionKeg's pile weight).
- **virtual/override members, name-mismatched backing fields (`m_`), exotic semantics** (guards' `Focus` does work on *equal* assignment; `ChampionSpawn.Active` never assigns its field).
Five sites the classifier refused were converted by hand where the hooks fit cleanly: `ReceiverCrystal.Sender`, `PlayerVendor.House`, `PlayerBarkeeper.House` (old-value unsubscribe via `oldValue`), `BaseSuit.AccessLevel` (its existing virtual `OnAccessLevelChanged` already had the exact callback shape), and `DyeTub.DyedHue` (a true veto: `AllowDyedHueChange(ref int value) => _redyable`).
## Verification
- Build: **0 errors, 0 warnings**.
- **Schema regeneration produces zero Migrations changes** — the conversion is wire- and schema-neutral by construction (same orders, types, and property names), and CI's schema diff check enforces it.
- **835 + 708 tests green.**
## Behavioral notes (all strict improvements, called out for review)
- Generated setters skip everything when the incoming value equals the current one; a few converted setters previously re-ran side effects on equal assignment (redundant `Update()`-style refreshes).
- Generated setters always `MarkDirty()` on change; several converted setters never did (e.g. `DyeTub.DyedHue`, `MorphItem` ranges) — their changes only persisted if something else dirtied the entity. Those latent persistence bugs are fixed by construction.
