Fix tournament bracket and group state corruption

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Bug and impact

• Editing a completed early-round category knockout match could reset only the directly affected match while leaving completed downstream rounds with stale teams/winners, corrupting bracket state in deeper brackets.
• Group rebalancing and direct groupIndex team updates remained possible after tournament play had started or matches were already live/completed, desynchronizing team group assignments from already-generated classification matches and corrupting standings/category seeding.

Root cause

• recomputeCategoryBracketAfterWinnerChange computed winner/loser feeders from a single snapshot and did not invalidate winners for matches reset during the same recomputation pass.
• rebalanceTournamentTeams and the team PATCH handler lacked the same post-start/locked-match guards used by group randomization.

Fix

• Recompute category bracket resets iteratively so resetting one match removes its winner/loser as valid inputs and propagates invalidation through all downstream dependents.
• Block group rebalancing once the tournament has started or any match is in progress/completed, and return a 400 response for rejected rebalance actions.
• Block team groupIndex PATCH changes after tournament start.
• Added focused regression tests for transitive bracket reset propagation and rebalance start/locked-match guards.

Validation

• npm test -- --run tests/knockoutAdvance.test.ts tests/rebalanceTournamentTeams.test.ts
• npm test
• npm run typecheck
• npm run lint (passes with existing warnings)

  

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Project	Deployment	Actions	Updated (UTC)
matchpoint	Ready	Preview, Comment	May 21, 2026 11:14am