Scoreboard widget: distinguish playoff weeks and label playoff / championship / 3rd-place matchups

[brandonpham13]

Problem

The Recent Scoreboard widget treats every week the same — a playoff week (e.g. semifinals, championship, 3rd-place) renders identically to a regular-season week. The user has no way to tell which weeks are postseason or what each playoff matchup represents.

Desired behavior

• Mark playoff weeks visually as separate from regular-season weeks (e.g. a "Playoffs" badge in the header, or a divider when navigating across the boundary).
• Label individual postseason matchups by round/role:
  • Quarterfinal / Semifinal / Championship
  • 3rd place / 5th place / consolation bracket
• Honor each league's actual playoff structure rather than assuming a fixed schedule.
• Show teams on bye (byes currently show on chopped league but not on redraft/dynasty)

Data sources

• Sleeper exposes playoff_week_start on the league settings — this gives the regular-season / playoff boundary.
• Winners and losers brackets are already wired up via useWinnersBracket / useLosersBracket (see client/src/hooks/useSleeper.ts). They include round, team1_roster_id, team2_roster_id, and place. These should be enough to label each matchup.

Notes

• Need to extend the League domain type (client/src/types/fantasy.ts and server/src/domain/fantasy.ts) to surface playoffWeekStart and likely playoffRoundType from Sleeper's league settings.
• Consider whether the regular-season standings widget should also reflect playoff seeding once the regular season ends.

[brandonpham13]

Update 5/11:

Playoff/Consolation/Championship games are marked correctly, except for 2 week championships. Week 18 needs special handling for those cases.

Still need to denote bye weeks for certain teams and possibly an actual playoff bracket in the future.