Save plan_cid to database immediately after plan creation

- Add plan_cid column to pending_runs table schema
- Add update_pending_run_plan() function to save plan_cid
- Update get_pending_run() to return plan_cid
- Save plan_cid right after storing plan to IPFS (before execution)
- Plan is now available even if run fails

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

legacy_tasks.py

@@ -649,6 +649,24 @@ def execute_recipe(self, recipe_sexp: str, input_hashes: Dict[str, str], run_id:
             plan_path = CACHE_DIR / plan_cid
             CACHE_DIR.mkdir(parents=True, exist_ok=True)
             plan_path.write_text(plan_sexp)
+
+            # Save plan_cid to database immediately so it's available even if run fails
+            if run_id:
+                import asyncio
+                import database
+                async def save_plan_cid():
+                    if database.pool is None:
+                        await database.init_db()
+                    await database.update_pending_run_plan(run_id, plan_cid)
+                try:
+                    loop = asyncio.get_event_loop()
+                    if loop.is_running():
+                        asyncio.ensure_future(save_plan_cid())
+                    else:
+                        loop.run_until_complete(save_plan_cid())
+                except RuntimeError:
+                    asyncio.run(save_plan_cid())
+                logger.info(f"Saved plan_cid to pending run: {run_id}")
     except Exception as e:
         logger.warning(f"Failed to store plan to IPFS: {e}")