fix: handle batch events format in manage_calendar tool (#3503)

* fix: handle batch events format in manage_calendar tool

Models like deepseek-v4-flash emit batch events array instead of individual create_event calls. The tool defaulted to list_events (no action key), so events were never created despite the model confirming success.

- Add batch normalization in do_manage_calendar

- Map start/end objects to flat dtstart/dtend strings

- Add tests for both object and flat string formats

* fix: surface partial batch failures in manage_calendar

Partial failures were silently dropped - batches with mixed success/failure would report only created count with no error visibility.

- Return non-zero exit code for any failures

- Surface both created and failed counts in response

- Include first error message for debugging

- Add test for partial failure case

* chore: strip trailing whitespace in batch normalization block

* chore: strip whitespace-only blank lines in batch events test

src/tool_implementations.py

@@ -1453,6 +1453,42 @@ async def do_manage_calendar(content: str, owner: Optional[str] = None) -> Dict:
     except ValueError:
         return {"error": "Invalid JSON arguments", "exit_code": 1}
 
+    # ── Batch normalization ──
+    # Some models (e.g. deepseek-v4-flash) emit {"events": [{...}, ...]}
+    # instead of individual create_event calls. Iterate and create each.
+    if isinstance(args.get("events"), list) and not args.get("action"):
+        results = []
+        for ev in args["events"]:
+            if not isinstance(ev, dict):
+                continue
+            # Normalize start/end from {dateTime: "..."} object to flat string
+            for field, target in [("start", "dtstart"), ("end", "dtend")]:
+                val = ev.pop(field, None)
+                if val and target not in ev:
+                    ev[target] = val.get("dateTime", val) if isinstance(val, dict) else val
+            ev.setdefault("action", "create_event")
+            r = await do_manage_calendar(json.dumps(ev), owner=owner)
+            results.append(r)
+        created = [r for r in results if r.get("exit_code") == 0 and not r.get("error")]
+        failed = [r for r in results if r.get("error")]
+
+        if not results:
+            return {"error": "No events to create", "exit_code": 1}
+
+        # Surface both successes and failures
+        parts = []
+        if created:
+            summaries = [r.get("response", "") for r in created]
+            parts.append(f"Created {len(created)} event(s):\n" + "\n".join(summaries))
+        if failed:
+            first_error = failed[0].get("error", "Unknown error")
+            parts.append(f"Failed to create {len(failed)} event(s). First error: {first_error}")
+
+        response = "\n\n".join(parts)
+        # Non-zero exit code for partial or total failure
+        exit_code = 0 if not failed else 1
+        return {"response": response, "exit_code": exit_code, "created_count": len(created), "failed_count": len(failed)}
+
     # Normalize action — some models emit hyphens ("list-calendars") instead
     # of underscores. Treat them as equivalent so we don't bounce a
     # cosmetic typo back to the model and waste a round-trip. Also accept