### 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.
- Added matchmaker configuration to local.yml with support for string property "mode"
- Enabled faster matchmaking via interval_ms and large ticket limit
- Broadcast initial match state when both players join
- Added detailed validation and logging for move processing
- Broadcast game-over and forfeit states immediately on player leave
- Improved MatchLoop robustness with change tracking and clearer diagnostics
- Track matches based solely on `player.match_id`
- Avoid double-counting from presence events or server broadcasts
- Ensure `matches[match_id]` contains only actual participants
- Prevent false 3–4 player matches and scenario execution failures
- Maintain safety check for non-1v1 match sizes
This resolves incorrect match grouping in automated matchmaking tests,
allowing clean 1v1 scenario execution and accurate match counts.
