feat: add persistent live and daily turn timers

[Enn3Developer]

No description provided.

[claude]

Claude finished @Enn3Developer's task in 36s —— View job

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Summary

Adds persistent turn timers to the server: games run either a Live mode (per-player time banks that tick only on their turn) or a Daily mode (24-hour deadlines with manual skip/kick), surviving reconnects and server restarts via snapshot persistence.

Changes

• Server: New TurnClock/TurnClockState (OpenPolytopia.Server/TurnClock.cs) tracks per-player banks, timeouts, elimination, and daily deadlines using injected now timestamps (no wall-clock reads, fully testable).
• Server: GameServer.Timers.cs wires clock polling into the request pipeline — expired live turns are auto-skipped/eliminated before each action (ProcessTimers), turn changes from any source resync the clock (SynchronizeClocks), and a new ResolveOverdueTurnPacket handler lets another player skip or kick an overdue daily turn.
• Server: GameServer.Persistence.cs bumps snapshot schema to version 2, persisting TurnClockState per session; legacy (v1) saves are migrated to a fresh Daily clock with a full 24h grace period.
• Common: Gameplay action packets (MoveTroop, Attack, TrainTroop, ResearchTech, Build, Capture, EndTurn) gain an ExpectedTurn field so stale/delayed requests are rejected after an automatic skip; new GameActionResult.InvalidParameters.
• Client: Lobby.cs renders the countdown, adds "Skip overdue turn"/"Kick overdue player" buttons (kick has a confirmation dialog) gated on daily mode and turn ownership.
• Tests: New TurnClockTest, GameServerTimerIntegrationTest, and TimerMigrationTest cover clock bookkeeping, end-to-end timer flows, and legacy-save migration.

Worth a look

• PacketRegistrar.cs moves _registered = true to after all packets are registered — fixes a potential race, but worth confirming intent since it's unrelated to the timer feature itself.
• Snapshot version bump (1→2) is a breaking change to save-file format; migration path for missing timer mode defaults to Daily with a fresh 24h window — confirm this default is acceptable for in-flight Live games upgraded from v1.
• ExpectedTurn semantics differ by mode (must match exactly in Live; 0 is accepted as "no guard" in Daily) — worth double-checking client call sites always populate it correctly for Live games.

[claude]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.