feat(playoffs): season playoff brackets

[ChronoFinale]

feat(playoffs): season playoff brackets

What

Season playoff brackets on the site, per Dunk's request to make playoffs more visible.

Public /playoffs tab (desktop nav + mobile menu)

• Rendered like the league's playoff sheet: two mirrored wings converging on a center column with the Champion box, Grand Finals, and Third Place Match — red match frames, black player boxes, blue score pills, Balatro m6x11 pixel font, connector elbows, gold winner names, crowned champion.
• Fully responsive, never scrolls horizontally: scales to fit down to 72%, then reflows into stacked round-by-round sections at full text size.
• Defaults to the active season's bracket; older seasons stay browsable via picker pills and /playoffs/{id}. Seed names linked to a player are profile links.

Admin /admin/brackets (new brackets.manage permission)

• Create = pick season (one bracket per season, enforced) + player count + third-place toggle. Series formats per bracket: Bo3/Bo5/… with a separate grand-finals format.
• The bracket itself is the editor: add players to a pool by searching the ranked leaderboard (rank + MMR, Discord id auto-linked) or typing any name; drag chips onto first-round spots (tap-tap works too), drag between spots to swap; type scores directly on the cards (auto-save after typing stops). Winners gold/advance instantly, losers grey.

How

• Only a roster and per-match scores are stored (brackets, bracket_seeds, bracket_results; single migration 0015). Pairings, advancement, semifinal-losers-to-third-place, and the champion are all derived in a pure bun-tested module (src/lib/bracket.ts) — the displayed bracket can never disagree with entered results, and correcting an old score reflows later rounds.
• Series semantics: a winner needs the majority of the best-of (a 1-0 in a Bo3 advances nobody), impossible scores like 2-2 in a Bo3 are rejected with a clear error, and rearranging placements clears exactly the stored results the change invalidates (changed matches + their downstream chain) so old scores can never decide new pairings.
• Brackets are owned by seasons (season_id NOT NULL + unique); display names derive from the season registry.
• Public procedures only expose published brackets.

Granting access

brackets.manage must be granted per user in /admin/permissions ("Manage brackets" under the Playoffs group) — permissions come from each user's stored permissions array, so nobody has bracket access until granted, existing admins included. Dunk logs in once via Discord to appear in the manager. The single permission unlocks only the bracket admin.

Follow-up (not in this PR)

Player-profile trophies ("Season X Playoff Champion" badge derived from published bracket results). The groundwork ships here — seeds carry Discord ids — and a working implementation is parked on feat/profile-trophies-wip.

Drive-by

• Added toMatchObject to the bun:test type shim (the bracket engine tests use it; typecheck fails without it).

Validation

bun test (32), bun run check, bun run typecheck, bun run build all green. Exercised end-to-end on local dev: created brackets via the admin UI, placed players, entered results, verified propagation/champion, published, checked public pages in both themes and at narrow widths.

[ChronoFinale]

Examples

Unfinished

Finished

Responsive on Mobile

[ershisan99]

I'm gonna merge this and if something breaks we'll fix ig