Performance & stability pass (issue #34 + audit)
General:
- DisableAll resets only skills active in the previous round instead of all loaded skills (~89ms -> ~5ms)
- Removed per-tick LINQ/allocations, O(1) HUD skill lookups, translation substitutions moved to load time
- ForceFullUpdate creates the network service once per broadcast; view-angle guard only skips a genuine (0,0,0) placeholder
- Debug hooks/logging only active when DebugMode is enabled (single reused writer)
- Player skill state unified to a single collection (fixes a rare disconnect race)
- Gamedata signatures resolved lazily/isolated; hardened tick/transmit paths against invalid handles
- Description HUD honours always-show / -1 duration consistently across all assignment paths
Skills:
- Jester: fixed the no-damage effect leaking after a mid-round skill change (Thief/Deactivator)
- Jackal: fixed trail entities accumulating over a round
- Falcon Eye / Third Eye / Spectator: camera state cleared on disable
Also: added missing translation keys as untranslated markers across language files.
Fixes#34
