Address PR review findings

- Fix papers last_sync timestamp comparison: use _parse_iso_datetime
  instead of string max() to avoid wrong result with mixed UTC offsets
- Fix dashboard /sync/health URL: pass community_id param so health
  badge reflects the viewed community, not always 'hed'
- Add tests for /sync/health community_id param: 404 for unknown,
  200 for known community

Author: neuromechanist

dashboard/osa/index.html

@@ -763,7 +763,7 @@ <h2>Communities</h2>
                 fetch(`${API_BASE}/${encodeURIComponent(communityId)}/metrics/public`),
                 fetch(`${API_BASE}/${encodeURIComponent(communityId)}/metrics/public/usage?period=${activePeriod}`),
                 fetch(`${API_BASE}/sync/status?community_id=${encodeURIComponent(communityId)}`).catch(err => { console.warn('Sync status fetch failed (non-critical):', err.message); return null; }),
-                fetch(`${API_BASE}/sync/health`).catch(err => { console.warn('Health check fetch failed (non-critical):', err.message); return null; }),
+                fetch(`${API_BASE}/sync/health?community_id=${encodeURIComponent(communityId)}`).catch(err => { console.warn('Health check fetch failed (non-critical):', err.message); return null; }),
             ]);
 
             const failedStatus = !summaryResp.ok ? summaryResp.status : (!usageResp.ok ? usageResp.status : null);

src/api/routers/sync.py

@@ -269,8 +269,12 @@ async def get_sync_status(
         matching = {
             k: v for k, v in metadata.get("papers", {}).items() if k.startswith(f"{source}:")
         }
-        timestamps = [v["last_sync"] for v in matching.values() if v.get("last_sync")]
-        last_sync = max(timestamps) if timestamps else None
+        parsed = [
+            (dt, raw)
+            for v in matching.values()
+            if (raw := v.get("last_sync")) and (dt := _parse_iso_datetime(raw))
+        ]
+        last_sync = max(parsed, key=lambda x: x[0])[1] if parsed else None
         papers_sources[source] = RepoStatus(
             items=stats.get(f"papers_{source}", 0),
             last_sync=last_sync,

tests/test_api/test_sync.py

@@ -192,6 +192,23 @@ def test_new_install_is_healthy(self, client: TestClient):
         data = response.json()
         assert data["status"] == "healthy"
 
+    def test_health_unknown_community_returns_404(self, client: TestClient):
+        """Unknown community_id should return 404 from health endpoint."""
+        response = client.get("/sync/health?community_id=does-not-exist")
+        assert response.status_code == 404
+
+    @pytest.mark.usefixtures("isolated_db")
+    def test_health_known_community_returns_200(self, client: TestClient):
+        """A registered community_id should return 200 from health endpoint."""
+        from src.assistants import registry
+
+        communities = registry.list_all()
+        if not communities:
+            pytest.skip("No communities registered")
+        community_id = communities[0].id
+        response = client.get(f"/sync/health?community_id={community_id}")
+        assert response.status_code == 200
+
 
 class TestSyncTrigger:
     """Tests for POST /sync/trigger endpoint."""