## Problem
`GetMonsterAbilities()` answers three questions through one virtual: which abilities a creature has (`GetAbility`, `AOS.cs` reflect/barrier, bard fire-breath difficulty), which abilities are enabled right now, and where cooldown state must be cleaned up (`InvalidateNextAbilityTriggers` on death and delete). Every caller assumes it is a pure, stable list. About 70 creatures return a static array; only LordOaks computed it:
```
Mobile.Delete()
→ BaseCreature.OnDelete() → CreatureDeletedEvent
→ MonsterAbility.InvalidateNextAbilityTriggers()
→ LordOaks.GetMonsterAbilities() → CheckQueen() → new Silvani().MoveToWorld(...)
```
- Deleting a Lord Oaks nobody had fought (champion reset, `DeleteCreatures`, GM delete) spawned an orphaned Silvani where he stood.
- The spell damage scalar (`AlterDamageScalarFrom`) spawned her too.
- With the queen dead his list was empty, so cleanup skipped his cooldown entries. The static `Dictionary<BaseCreature, long>` on the ability singleton kept a reference to the deleted creature. `MonsterAbilityGroup` children's entries were never cleaned either.
- Neira threw unholy bones from `AlterDamageScalarFrom`, so any caller asking for a damage scalar (a preview gump, for example) could fire the effect.
## Changes
- **Per-creature cooldowns:** a lazy `Dictionary<MonsterAbility, long>` on `BaseCreature` (`IsAbilityOnCooldown`, `SetAbilityCooldown`, `ClearAbilityCooldowns`). The static dictionaries and the query-driven cleanup are gone, and death still resets cooldowns. Tick comparisons are wraparound-safe.
- **Pure contract:** `GetMonsterAbilities()` is documented as pure. The new `virtual bool CanUseAbility(MonsterAbility)` gates abilities that only work some of the time. Every `TriggerAbility*` loop and `GetAbility` check it.
- **LordOaks:** always lists his abilities; `CanUseAbility` and the 10% spell shield read "queen alive". The queen spawns when he is first aggressed or first given a combatant, never on the internal map. Aggression lands before the damage it causes, so the first spell is still shielded, as before.
- **Neira:** the unholy bone throw moves to `OnDamagedBySpell`.
A follow-up PR makes minions such as the queen, pixies and Barracoon's rats belong to their champion spawn, so a spawn reset cleans them up.
## Testing
- `LordOaksTests` covers three cases:
- querying or deleting an unengaged Lord Oaks spawns nothing;
- aggression spawns the queen exactly once, and the shield and abilities follow her life;
- an Oaks on the internal map never spawns her.
- UOContent.Tests: 1234 passed, 2 skipped.
- A local constructor sweep (every Mobile built and deleted repeatedly) no longer reports LordOaks.
The pure SerializationGenerator conversion of `BaseCreature`, split out of #2592 so it can serve as the reference for converting every other large hand-written class in the Delta Saves project (#7, phase 3). Two behaviour changes from #2592 are deliberately not here and follow in their own PRs on top of this one: `SpeedClass`, and the collapse of `ControlMaster`/`SummonMaster` into one reference (a creature can lose or keep either independently: Blade Spirits and Energy Vortexes are summoned but never controlled, EnragedCreature and talisman summons keep a summon master with neither flag set).
## What this is
- `BaseCreature` becomes `[SerializationGenerator(23, false)]` with a `[SerializableField]` per serialized slot and `[SaveFlag]` elision on nearly every field, so a stock creature serializes to its version plus flags. Field orders run 0..53 with no gaps (54 fields).
- The hand-written reader stays as `private void Deserialize(IGenericReader reader, int version)` for every pre-codegen version (0..22); post-codegen bumps use `MigrateFrom` from here on. `[AfterDeserialization]` carries the post-load fixups main did after reading (stat timers, AI type, followers, reacquire seeding).
- `ControlMaster` and `SummonMaster` stay two independent fields with main's semantics, each elided when null.
- `DamageMin`/`DamageMax`/`ActiveSpeed`/`PassiveSpeed` are no longer virtual (nothing in the tree overrode them); comments swept to the constraints that matter.
- Direct writes to serialized backing fields outside the generated setters (`SetDamage`, `SetResistance`, the move-speed helpers, the loot flag, feed loyalty, the delete timer) call `this.MarkDirty()`, matching the #2609 standard, so the class is ready for delta saves once `Mobile` is audited.
- Schema `Server.Mobiles.BaseCreature.v23.json` regenerated by the tool (a second run produces no diff).
## Deferred to follow-up PRs
SpeedClass: the serialized `_speedClass` field, `DefaultSpeedClass` replacing the type constant, `ApplySpeedClass`/`OnSpeedClassChange`, "None means custom", the four-speeds-as-one-block elision, `NPCSpeeds.FindEntry(SpeedLevel)`, the constructor fallback to Medium, and their tests.
Master references: serializing one `Master` with a `Controlled`/`Summoned` fan-out and the `SetControlMaster` lockstep.
## Tests
UOContent.Tests 776 / Server.Tests 855 green. `BaseCreatureSerializationTests` covers: a default creature elides to version + flags; a populated creature round-trips with exact byte consumption; back-to-back saves are byte-identical; an uncontrolled summon keeps its SummonMaster; byte-authentic v22 legacy streams (replicas of main's `Serialize`) load through the legacy reader for a wild tamable, a controlled pet, a controlled summon with an anchored `SummonEnd`, and a summon-master-only creature (the EnragedCreature shape); a running delete timer round-trips through `[DeserializeTimer]`; `Friends`, `CurrentWayPoint` and `HomeMap` round-trip; a `BaseVendor` stub round-trips the generated BaseVendor v2 → generated BaseCreature v23 chain.
## Behaviour notes for reviewers
- `ActiveMoveSpeed`/`PassiveMoveSpeed` getters return the raw override (0 = inherit); `CurrentMoveSpeed` is the resolved pace.
- Speeds elided as table defaults re-snap to the current `npc-speeds.json` on load, so table edits reach unmodified spawns on restart.
- `GetSpeeds` no longer throws on the save/load path when the table has no entry for the type: saves elide against the creature's own values and loads keep the stream. Construction still throws (`InvalidOperationException`, was `KeyNotFoundException`). An elided load with no table entry would otherwise resume at speed 0, so `[AfterDeserialization]` logs once and paces it at Medium.
- `virtual` removed from `ActiveSpeed`, `PassiveSpeed`, `DamageMin`, `DamageMax` (no overrides in the tree; forks may have some).
- `ControlMaster`, `SummonMaster`, `ControlOrder`, `Tamable`, `IsParagon` are `[SerializableProperty]` over hand-written setters because follower bookkeeping must run before the assignment, which a `fieldChanged` hook cannot express; the wire format is identical.
## Prerequisites for cherry-picking
#2609 (BaseVendor is already generated on top of BaseCreature) and SerializationGenerator 4.1.0.
## **MAJOR CHANGE**
* `Stabled` has been moved to `PlayerMobile`.
* New methods added, `PlayerMobile.AddStabled` and `PlayerMobile.RemoveStabled`.
* Added `PlayerMobile.AddFollower` and `PlayerMobile.RemoveFollower`.
* `Stabled`, `AutoStabled`, and `AllFollowers` are now `HashSet` and **_CAN BE NULL_**.
### Summary
* Fixes monster abilities causing harm to the monster through reflect
* Adds `CanTriggerAgainstSelf` to override this for healing or some other self-affecting ability
* Fixes a major memory leak where `UnsummonTimer` from animated dead spell lasts up-to 24hrs and therefore holds onto references of dead/deleted mobs.
* Fixes another minor leak where a mob is not unregistered from the animated dead spell list until the next spell cast.
