feat: portfolio context injection + AI call log viewer

Portfolio context (portfolio_context.py):
- get_open_trades_with_moves(): fetches open trades + 1d/5d yfinance price moves
- get_portfolio_concentration(): counts by asset_class
- build_portfolio_context_block(): formatted prompt block with strict AI instructions
  (no double positions, flag contradictions, avoid overweight classes)

AI call logging:
- ai_call_logs table in DB (run_id, call_type, system/user prompt, response, tokens, ms)
- _chat() now accepts log_meta dict → saves call to DB non-blocking after each call
- suggest and score_batch calls pass run_id + call_type for full traceability

auto_cycle.py:
- Builds portfolio context before snapshot and both AI calls
- Context snapshot now includes portfolio_open_positions key

SystemLogs.tsx:
- "Contexte IA" tab gains sub-tabs: Contexte / Appels IA
- AiCallRow: expandable with 3 panes (user prompt / system prompt / response)
  shows model, tokens breakdown, duration, call type badge

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

backend/routers/cycle.py

@@ -1,7 +1,7 @@
 from fastapi import APIRouter, HTTPException
 from pydantic import BaseModel
 from typing import Optional
-from services.database import get_cycle_runs, get_cycle_run, set_config, get_config, list_cycle_context_snapshots, get_cycle_context_snapshot
+from services.database import get_cycle_runs, get_cycle_run, set_config, get_config, list_cycle_context_snapshots, get_cycle_context_snapshot, get_ai_call_logs
 from services.auto_cycle import get_status, trigger_manual, restart_scheduler
 
 router = APIRouter(prefix="/api/cycle", tags=["cycle"])
@@ -100,6 +100,13 @@ def get_context_snapshot(run_id: str):
     return snap
 
 
+@router.get("/ai-calls/{run_id}")
+def get_cycle_ai_calls(run_id: str):
+    """Return all AI calls logged for a given cycle run_id."""
+    calls = get_ai_call_logs(run_id)
+    return {"run_id": run_id, "calls": calls, "count": len(calls)}
+
+
 class ReplayRequest(BaseModel):
     override_notes: Optional[str] = None  # optional annotation added to the replay