feat(throwing): add Ter Mur reptiles (Raptor + slith family) and their SA claws (#2515)

Follow-up to the gargoyle Throwing work (#2510/#2512/#2514). Ports two Stygian Abyss creatures from ServUO so two of the throwing artifacts finally have a real OSI drop source instead of being `[add`-only.

## Changes
- **`Raptor`** and **`StoneSlith`** — ported stat-for-stat from ServUO. They **spawn automatically**: `Distribution/Data/Spawns/post-uoml/termur/TerMur.json` already contained Raptor/StoneSlith spawner entries referencing these class names, so no spawn-file edits were needed.
- **`RaptorClaw`** (Boomerang-based) and **`StoneSlithClaw`** (Cyclone-based) artifacts, dropped from each creature's `OnDeath` at ServUO's 0.5% rate (uncontrolled only).
- StoneSlith retains its `GraspingClaw` monster ability; both use `BleedAttack`.

## ModernUO idioms
Default range perception (16) / fight range, derived `GetSpeeds` (no `SetSpeed`), `[SerializationGenerator(0)]` codegen, collection-expression arrays.

## Documented omissions vs ServUO
Flagged as TODO in-code — all are content missing from ModernUO, not silent drops: Raptor's friend-spawn timer + its 25% `AncientPotteryFragments` drop; StoneSlith's `TailSwipe`, `DragonBlood`, and `SlithEye`/`TatteredAncientScroll`/`AncientPotteryFragments` drops; plus `HideType.Horned/Spined` and `PackInstinct.Ostard` (no ModernUO equivalents yet).

## Not included
The other three throwing artifacts (Storm Caller, Banshee's Call, Wind of Corruption) drop from renowned/boss creatures via a `BaseRenowned` artifact-list system that doesn't exist in ModernUO yet — a separate, larger effort. AbyssReaver stays with the (deferred) Into-the-Void quest.

Verified: server builds clean; throwing suite 14/14.

Projects/UOContent/Items/Weapons/SlayerGroup.cs

@@ -342,6 +342,7 @@ namespace Server.Items
                 typeof(OphidianMage),
                 typeof(OphidianMatriarch),
                 typeof(OphidianWarrior),
+                typeof(Raptor),
                 typeof(Reptalon),
                 typeof(SeaSerpent),
                 typeof(Serado),
@@ -350,6 +351,9 @@ namespace Server.Items
                 typeof(SilverSerpent),
                 typeof(SkeletalDragon),
                 typeof(Snake),
+                typeof(Slith),
+                typeof(StoneSlith),
+                typeof(ToxicSlith),
                 typeof(SwampDragon),
                 typeof(WhiteWyrm),
                 typeof(Wyvern),