### Highlights
- Introduced generic match engine (`generic_match.go`) implementing dynamic GameRules-based runtime.
- Added modular structure under `/plugins`:
- /plugins/game → GameRules interface + TicTacToe + Battleship rule sets
- /plugins/structs → Board, Player, MatchState generic structs
- /plugins/modules → matchmaking + RPC handlers + match engine
- Migrated TicTacToe logic into reusable rule implementation.
- Added Battleship game support using same engine.
- Updated matchmaking to accept { game, mode } for multi-game routing.
- Updated UI contract: clients must send `game` (and optional `mode`) when joining matchmaking.
- Removed hardcoded TicTacToe match registration.
- Registered a single “generic” authoritative match with ruleset registry.
- Normalized imports under local dev module path.
- Ensured MatchState and Board are now generic and reusable across games.
- Added strict requirement for `game` metadata in match flow (error if missing).
- Cleaned initial state creation into MatchInit with flexible board dimensions.
- Improved MatchLeave for proper forfeit handling through GameRules.
### Result
The server now supports an unlimited number of turn-based board games
via swappable rulesets while keeping a single authoritative Nakama match loop.
- Implement rpc_find_match Nakama RPC function
- Search for existing authoritative TicTacToe matches via MatchList
- Return first match with available slot (size < 2)
- Create new match using MatchCreate when none available
- Add request/response structs for future extensibility
- Log match search, selection, and creation flow
- Gracefully handle optional JSON payload and invalid input
