feat: Timeline Navigator — contexte historique 3 temporalités COVID → aujourd'hui

- 2 nouvelles tables SQLite : market_events + timeline_context
- 32 événements historiques seedés (long/medium/short de feb 2020 à juin 2026)
- timeline_service.py : bootstrap, get_events_for_date, génération commentaires GPT-4o-mini
- /api/timeline router : GET /day/{date}, GET /events, POST /generate/{date}, POST /bootstrap
- Timeline.tsx : navigateur date avec strip visuel, 3 panneaux contextuels, catalogue d'événements
- Sidebar : entrée Timeline avec icône Layers

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/routers/timeline.py

@@ -0,0 +1,113 @@
+"""
+Timeline Navigator — historical market context browser.
+Prefix: /api/timeline
+"""
+import logging
+from typing import Any, Dict, List, Optional
+
+from fastapi import APIRouter, HTTPException
+from pydantic import BaseModel
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/api/timeline", tags=["timeline"])
+
+
+class EventCreate(BaseModel):
+    name: str
+    start_date: str
+    end_date: Optional[str] = None
+    level: str  # long | medium | short
+    category: str = "macro"
+    description: str = ""
+    market_impact: str = ""
+    affected_assets: List[str] = []
+    impact_score: float = 0.5
+    parent_event_id: Optional[int] = None
+
+
+class EventUpdate(EventCreate):
+    pass
+
+
+@router.get("/events")
+def list_events() -> List[Dict[str, Any]]:
+    from services.database import get_all_market_events
+    return get_all_market_events()
+
+
+@router.post("/events")
+def create_event(body: EventCreate) -> Dict[str, Any]:
+    from services.database import save_market_event
+    new_id = save_market_event(body.dict())
+    return {"id": new_id, "status": "created"}
+
+
+@router.put("/events/{event_id}")
+def update_event(event_id: int, body: EventUpdate) -> Dict[str, Any]:
+    from services.database import update_market_event
+    ok = update_market_event(event_id, body.dict())
+    if not ok:
+        raise HTTPException(404, "Event not found")
+    return {"status": "updated"}
+
+
+@router.get("/day/{ref_date}")
+def get_day_context(ref_date: str) -> Dict[str, Any]:
+    """Return cached or freshly generated timeline context for a date (YYYY-MM-DD)."""
+    from services.database import get_events_for_date, get_timeline_context
+    import json
+
+    events = get_events_for_date(ref_date)
+    cached = get_timeline_context(ref_date)
+
+    result: Dict[str, Any] = {
+        "ref_date": ref_date,
+        "events": events,
+        "long_commentary": "",
+        "medium_commentary": "",
+        "short_commentary": "",
+        "evidence_headlines": [],
+        "generated_at": None,
+        "has_commentary": False,
+    }
+    if cached:
+        result.update({
+            "long_commentary": cached.get("long_commentary", ""),
+            "medium_commentary": cached.get("medium_commentary", ""),
+            "short_commentary": cached.get("short_commentary", ""),
+            "evidence_headlines": json.loads(cached.get("evidence_headlines", "[]") or "[]"),
+            "generated_at": cached.get("generated_at"),
+            "has_commentary": bool(cached.get("long_commentary")),
+        })
+    return result
+
+
+@router.post("/generate/{ref_date}")
+def generate_commentary(ref_date: str) -> Dict[str, Any]:
+    """Generate (or regenerate) AI commentary for a specific date and cache it."""
+    from services.timeline_service import get_or_generate_context
+    import json
+
+    try:
+        ctx = get_or_generate_context(ref_date)
+        return {
+            "ref_date": ref_date,
+            "long_commentary": ctx.get("long_commentary", ""),
+            "medium_commentary": ctx.get("medium_commentary", ""),
+            "short_commentary": ctx.get("short_commentary", ""),
+            "evidence_headlines": json.loads(ctx.get("evidence_headlines", "[]") or "[]") if isinstance(ctx.get("evidence_headlines"), str) else ctx.get("evidence_headlines", []),
+            "events": ctx.get("events", {}),
+            "has_commentary": True,
+        }
+    except Exception as e:
+        logger.error(f"[Timeline] generate_commentary failed for {ref_date}: {e}")
+        raise HTTPException(500, str(e))
+
+
+@router.post("/bootstrap")
+def bootstrap_events() -> Dict[str, Any]:
+    """Seed historical market events (idempotent — only runs if table is empty)."""
+    from services.timeline_service import bootstrap_events as _bootstrap
+    count = _bootstrap()
+    return {"seeded": count, "status": "ok" if count > 0 else "already_seeded"}