feat: 12h status report + behavior choreography (REQ-015,070-076,094-099)

[cskwork]

Summary

• §9.8 idle-triggered 12h status report (REQ-070..076) replaces the fixed daily reflection. Frontend gate (statusReportGate.ts) requires 12h elapsed AND idle/sleep ≥60s AND not in-flight; no catch-up for missed windows. Backend compiles a summary-statistics payload (event counts, salience sum, mood distribution, top-3 memories — never raw user input), runs the LLM with strict JSON validation, and falls back to a deterministic generator on any failure. Reports land under pet_home/dreams/YYYY-MM-DD-HHMM.md.
• §9.11 behavior choreography (REQ-094..099) — LLM picks {preset, variant, bubble} from a closed catalog of 8 presets × 1-3 variants over MovementState. Bubbles are restricted to a closed vocabulary (10 glyphs/onomatopoeia). Free-text replies are rejected and replaced by a deterministic mood × event fallback so the pet always reacts visibly. Shares the existing 90s autonomous LLM cooldown with chat (REQ-097).
• REQ-015 expressive sprites — 8 new MovementState poses (stretch, peek, tilt_head, shake, nuzzle, wiggle, dizzy, surprise) generated via codex-cli image_gen, anchored to mochi-idle.png for tone consistency.
• DB migration is non-destructive: pet_state.last_report_at added via PRAGMA table_info-guarded ALTER; daily_reflections table retained alongside the new status_reports table.
• Settings UI — Sandbox tab replaces "Last dream" with "Recent status reports" (powered by list_status_reports); the manual "Run daily reflection" button becomes "Run status report now".

Test plan

• cargo test --lib — 75 passing (was 41, +34 new)
• npm test — 128 passing (was 99, +29 new)
• npm run check — 0 errors / 0 warnings (303 files)
• Manual: npm run tauri:dev, drop a .md into inbox/, approve → observe multi-frame choreography with a closed-token bubble (no human sentences)
• Manual: Settings → Sandbox → "Run status report now" → file lands under dreams/, "Recent status reports" populates, pet stays silent
• Manual: stop Ollama, click "Run status report now" again → deterministic fallback prose still produces a 200-400 char paragraph
• Manual: legacy DB migration — open with a pre-§9.8 user database to verify last_report_at is added without data loss
• Manual: 30+ minute return → existing chat path still works (USER_RETURNED branch unchanged)

Notes

• E2E deferred to BACKLOG #21 — Tauri webview e2e cannot be driven by stock Playwright; needs tauri-driver + webdriverio. Pure logic is already covered by statusReportGate.test.ts (10 tests) and choreography.test.ts (19 tests).
• Sprites are 1024x1024 (Codex's smallest supported size). Rendered at ~140px so file size impact is minor; a build-time downscale could trim disk usage if needed.
• daily_reflections table + run_daily_reflection command retained for backwards compatibility but no longer surfaced in the UI.

30 files changed, 3062 insertions(+), 64 deletions(-).