Halit Aksoy af11fd1cf1 feat(backend): save the series of each game

Migration 004_series adds games.series_id with an index, so the history
can group a series later. Games saved before have none.

2026-10-17 02:04:24 +03:00

Rematch and series: tasks

Work through the tasks in order; each ends with its tests passing and a commit. Tick a task when it is committed.

1. Spec: requirements, design and tasks.
2. Series in live games: Series, SeriesGame, BackendGame.series and firstSeat(), the first seat in createMancalaGame; series and firstSeat in ClientGame and GameEndMessage, series in snapshots (with the restore of old snapshots); unit and serialisation tests.
3. Rematch requests: RematchOffers, the four channels, the timers on the Scheduler, ending requests on new_game, new_bot_game and going offline, the bot accepting at once; unit tests.
4. Saving: seriesId in GameRecord, migration 004_series, the repository; integration tests.
5. Core: channel names, types, getSeriesScore, texts in English and Turkish; unit tests.
6. Web app, rematch: the game page following on_game_start (key={gameId}), the game over card's rematch states, "Play again" as a rematch, the score in two columns.
7. Web app, series strip: SeriesStrip, the series score on the game over card, spectators.
8. End to end and docs: the Chrome tests from design.md; AGENTS.md (the specs list, rematch notes), TODO.md (the out of scope items; remove "A rematch button" from Web redesign), the web redesign design's note on the rematch button.