Add honeycomb completion heatmap and data migration framework

- Add completion_summary endpoint data to residence detail response
- Track completed_from_column on task completions (overdue/due_soon/upcoming)
- Add GetCompletionSummary repo method with monthly aggregation
- Add one-time data migration framework (data_migrations table + registry)
- Add backfill migration to classify historical completions
- Add standalone backfill script for manual/dry-run usage

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

internal/services/residence_service.go

@@ -58,8 +58,9 @@ func (s *ResidenceService) SetSubscriptionService(subService *SubscriptionServic
 	s.subscriptionService = subService
 }
 
-// GetResidence gets a residence by ID with access check
-func (s *ResidenceService) GetResidence(residenceID, userID uint) (*responses.ResidenceResponse, error) {
+// GetResidence gets a residence by ID with access check.
+// The `now` parameter is used for timezone-aware completion summary aggregation.
+func (s *ResidenceService) GetResidence(residenceID, userID uint, now time.Time) (*responses.ResidenceResponse, error) {
 	// Check access
 	hasAccess, err := s.residenceRepo.HasAccess(residenceID, userID)
 	if err != nil {
@@ -78,6 +79,17 @@ func (s *ResidenceService) GetResidence(residenceID, userID uint) (*responses.Re
 	}
 
 	resp := responses.NewResidenceResponse(residence)
+
+	// Attach completion summary (honeycomb grid data)
+	if s.taskRepo != nil {
+		summary, err := s.taskRepo.GetCompletionSummary(residenceID, now, 10)
+		if err != nil {
+			log.Warn().Err(err).Uint("residence_id", residenceID).Msg("Failed to fetch completion summary")
+		} else {
+			resp.CompletionSummary = summary
+		}
+	}
+
 	return &resp, nil
 }