Add web upload: drag-and-drop images to depot via browser

- POST /api/upload saves files to /depot/ for ingest processing
- Batches of 10 files per request
- Drag-and-drop zone + file picker, per-file status feedback
- New 'Last opp'-tab in navbar

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

backend/api.py

@@ -156,6 +156,43 @@ async def get_results_endpoint(db=Depends(get_connection)):
     return await get_results(db)
 
 
+# =====================
+# Bildeopplasting
+# =====================
+
+VALID_IMAGE_TYPES = {"image/jpeg", "image/png"}
+VALID_IMAGE_SUFFIXES = {".jpg", ".jpeg", ".png"}
+
+
+@app.post("/api/upload", summary="Last opp ett eller flere bilder til depot")
+async def upload_images(files: list[UploadFile] = File(...)):
+    """
+    Lagrer opplastede bilder i /depot/ slik at ingest-prosessen plukker dem opp.
+    Returnerer status per fil.
+    """
+    results = []
+    for file in files:
+        suffix = Path(file.filename).suffix.lower()
+        if suffix not in VALID_IMAGE_SUFFIXES:
+            results.append({"filename": file.filename, "ok": False, "error": "Ugyldig filtype"})
+            continue
+
+        dest = Path("/depot") / file.filename
+        # Unngå overskrivning ved navnekollisjon
+        if dest.exists():
+            import uuid as _uuid
+            dest = Path("/depot") / f"{_uuid.uuid4().hex}_{file.filename}"
+
+        try:
+            content = await file.read()
+            dest.write_bytes(content)
+            results.append({"filename": file.filename, "ok": True, "saved_as": dest.name})
+        except Exception as e:
+            results.append({"filename": file.filename, "ok": False, "error": str(e)})
+
+    return {"uploaded": sum(1 for r in results if r["ok"]), "results": results}
+
+
 # =====================
 # Bilder
 # =====================