Phase 2 follow-up to #2510 — wires acquisition for the gargoyle Throwing content that Phase 1 deliberately left out.
## Changes
- **SA loot flavor (`IsStygian`)** — completes the dead loot path from the original PR: adds `SAWeaponTypes`/`SARangedWeaponTypes` pools + `isStygian` branches to `Loot.RandomWeapon`/`RandomRangedWeapon`, **and** the missing piece — computes `IsStygian` (`map == Map.TerMur`) in `LootPackEntry.Construct` and threads it through `LootPackItem.Construct`. Ter Mur creatures now roll SA gear + the three throwing weapons (Boomerang/Cyclone/SoulGlaive) from their normal `BaseWeapon`/`BaseRanged` loot entries. Conservative `TerMur`-only (not ServUO's extra `|| RandomBool()`).
- **Valkyrie's Glaive** — re-added as a self-contained Ter Mur stealable artifact at `(843, 665, 27)`, matching ServUO/OSI, with the previously-missing `ArtifactRarity => 5`.
## Deferred (documented)
The 5 host-dependent artifacts (Raptor Claw, Stone Slith Claw, Storm Caller, Banshee's Call, Wind of Corruption) are intentionally NOT included — their OSI drop sources (Raptor, StoneSlith, and the renowned/boss creatures + a `BaseRenowned` artifact-list system) don't exist in ModernUO yet, so re-adding the items now would leave them `[add`-only. They'll follow a dedicated SA-creatures effort.
## Notes
- No new tests: both changes are property/plumbing with RNG-driven output — no deterministic complex logic to assert (consistent with the repo's test-scope conventions).
- Verified: server + test project compile; throwing suite 14/14.
### 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">
### Summary
- [X] Fixed a bug where entity persistence was serialized out of order, causing world corruption.
- [X] Fixed LastSerialized not being utilized properly and dangling references still becoming an issue.
- [X] Added a new `GenericEntityPersistence<T>` type to encapsulate `ISerializable` serialization.
- [X] Removing the custom logic and moved Items, Mobiles, Guilds, and Accounts to GenericEntityPersistence.
- [X] Changed serialization to use the singleton pattern to reduce calling methods from stored variables.
