feat: add template selector to batch detail for CV generation

main.py

@@ -913,12 +913,12 @@ async def get_batch(batch_id: str):
 
 @app.put("/api/batches/{batch_id}")
 async def update_batch(batch_id: str, request: Request):
-    """Update batch name/description."""
+    """Update batch name/description/template."""
     body = await request.json()
     row = db.execute(
-        """UPDATE cv_batches SET name = %s, description = %s, updated_at = NOW()
+        """UPDATE cv_batches SET name = %s, description = %s, template_id = %s, updated_at = NOW()
            WHERE id = %s RETURNING *""",
-        (body.get("name"), body.get("description"), batch_id)
+        (body.get("name"), body.get("description"), body.get("template_id"), batch_id)
     )
     if not row:
         raise HTTPException(404, "Batch not found")