fix: FF calendar upload endpoint + path resolution for server deployment

- Add POST /api/eco/ff-upload to receive CSV from browser (saves to /tmp)
- _find_csv() checks /tmp, /app, project root — works local + Docker
- _run_ff_import now takes explicit csv_path parameter
- Frontend: Upload CSV button (file input) → uploads to server first,
  then Import into DB — with upload progress messages

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

backend/routers/eco.py

@@ -7,7 +7,7 @@ import logging
 import os
 from typing import Any, Dict, List, Optional
 
-from fastapi import APIRouter, BackgroundTasks, HTTPException, Query
+from fastapi import APIRouter, BackgroundTasks, File, HTTPException, Query, UploadFile
 
 logger = logging.getLogger(__name__)
 router = APIRouter(prefix="/api/eco", tags=["Economic Calendar"])
@@ -296,17 +296,27 @@ def upcoming_events() -> List[Dict[str, Any]]:
 _ff_import_status: Dict[str, Any] = {"running": False, "last_result": None}
 _ff_sync_status:   Dict[str, Any] = {"running": False, "last_result": None}
 
-_FF_CSV_PATH = os.path.join(
-    os.path.dirname(__file__), "..", "..", "forex_factory_cache.csv"
-)
+# CSV may sit at project root (local dev) or in /tmp (uploaded via browser on server)
+_FF_CSV_CANDIDATES = [
+    "/tmp/forex_factory_cache.csv",
+    os.path.join(os.path.dirname(__file__), "..", "forex_factory_cache.csv"),
+    os.path.join(os.path.dirname(__file__), "..", "..", "forex_factory_cache.csv"),
+]
 
 
-def _run_ff_import():
+def _find_csv() -> str | None:
+    for p in _FF_CSV_CANDIDATES:
+        full = os.path.abspath(p)
+        if os.path.exists(full):
+            return full
+    return None
+
+
+def _run_ff_import(csv_path: str):
     global _ff_import_status
     _ff_import_status["running"] = True
     try:
         from services.ff_calendar import import_csv
-        csv_path = os.path.abspath(_FF_CSV_PATH)
         result = import_csv(csv_path)
         _ff_import_status["last_result"] = result
     except Exception as e:
@@ -330,15 +340,30 @@ def _run_ff_sync():
         _ff_sync_status["running"] = False
 
 
+@router.post("/ff-upload")
+async def ff_upload(file: UploadFile = File(...)) -> Dict[str, Any]:
+    """Upload forex_factory_cache.csv directly from the browser (saves to /tmp)."""
+    dest = "/tmp/forex_factory_cache.csv"
+    try:
+        content = await file.read()
+        with open(dest, "wb") as f:
+            f.write(content)
+        size_mb = round(len(content) / 1_048_576, 1)
+        print(f"[FF upload] Saved {size_mb} MB to {dest}", flush=True)
+        return {"status": "uploaded", "path": dest, "size_mb": size_mb}
+    except Exception as e:
+        raise HTTPException(500, f"Upload failed: {e}")
+
+
 @router.post("/ff-import")
 def ff_import(background_tasks: BackgroundTasks) -> Dict[str, Any]:
     """Import forex_factory_cache.csv into ff_calendar table (background)."""
     if _ff_import_status["running"]:
         raise HTTPException(409, "Import already running")
-    csv_path = os.path.abspath(_FF_CSV_PATH)
-    if not os.path.exists(csv_path):
-        raise HTTPException(404, f"CSV not found: {csv_path}")
-    background_tasks.add_task(_run_ff_import)
+    csv_path = _find_csv()
+    if not csv_path:
+        raise HTTPException(404, "CSV not found. Upload it first via POST /api/eco/ff-upload")
+    background_tasks.add_task(_run_ff_import, csv_path)
     return {"status": "started", "csv": csv_path}