feat(frontend): R1 Tournament Dashboard — Vite+React live match observer

[LeoLin990405]

Summary

R1 frontend layer (antigravity). Stacks on PR #10 (backend robustness).

• Live Tournament tab — 4 parallel TerminalPanel components stream match events. Mock simulation plays 4-civ scenario (Tang/Rome/Soviet/Prussia) with timestamped role turns. JudgeLeaderboard appears on completion with legality/feasibility/resilience scores and per-civ AI verdict.
• Match Archive tab — lists ~/.civagent/matches/ (B4 structured) and ~/.civagent/transcripts/ (legacy fallback), sorted by mtime. Click a match to load its events.jsonl and display turn-by-turn playback + actual sedimented skill events in the timeline (not hardcoded).
• Regimes Codex tab — grid of all 57 regimes with pattern filter (centralized / checks-and-balances / democratic / dual-track / federation / theocratic), search by id/tag, IDENTITY.md + SOUL.md preview, sedimented skills count.

Architecture

Vite dev server (port 5173)
  └── civagentApiPlugin (vite.config.ts middleware)
        ├── GET /api/regimes       → reads regimes/*/metadata.json + IDENTITY/SOUL/skills
        ├── GET /api/matches       → ~/.civagent/matches/<id>/meta.json (B4)
        │                            + ~/.civagent/transcripts/*.jsonl (legacy)
        ├── GET /api/matches/:id   → events.jsonl lines parsed as MatchEvent[]
        └── GET /api/tournaments   → ~/.civagent/tournaments/*/manifest.json

No separate backend process. Frontend reads files directly via Vite middleware during development; production build would need a thin static server with the same routes.

Data contract alignment

• MatchEvent type matches schemas/match-event.schema.json (B4, from PR feat(engine): R1 backend robustness — remove Gemini, fix tournament race, wire backends #10)
• TournamentManifest type corrected to match actual tournament.mjs output:
  • civs: TournamentCiv[] (objects with regime/backend/matchId/exitCode/events)
  • judge: { provider, resultPath } (absolute paths, fixed in PR feat(engine): R1 backend robustness — remove Gemini, fix tournament race, wire backends #10 review)
• HistoryExplorer Skill Timeline reads live skill events instead of hardcoded placeholder

Test plan

• cd frontend && npm run dev — starts on :5173 with no errors
• /api/regimes returns 58 entries (including _template)
• Live Tournament → "Run Simulation" → 4 panels animate in parallel, leaderboard appears after ~14s
• Match Archive → empty until a real civagent run --v5 match completes
• Regimes Codex → filter by "checks-and-balances" narrows list; click regime shows IDENTITY preview
• TypeScript: npx tsc --noEmit → 0 errors