feat(labels): standardize automatic label creation to match ecosystem convention

@goal: WHOOSH-LABELS-004, WSH-CONSISTENCY - Ecosystem standardization

Replace custom label set with standardized CHORUS ecosystem labels:
- Add all 8 GitHub-standard labels (bug, duplicate, enhancement, etc.)
- Fix bzzz-task color from #ff6b6b to #5319e7 for consistency
- Remove custom priority labels and whoosh-monitored label
- Maintain backward compatibility and error handling

Changes:
- Updated EnsureRequiredLabels() in internal/gitea/client.go
- Added requirement traceability comments throughout
- Updated integration points in internal/server/server.go
- Created comprehensive decision record

Benefits:
- Consistent labeling across WHOOSH, CHORUS, KACHING repositories
- Familiar GitHub-standard labels for better developer experience
- Improved tool integration and issue management
- Preserved bzzz-task automation for CHORUS workflow

Fixes: WHOOSH issue #4

🤖 Generated with [Claude Code](https://claude.ai/code)

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

internal/gitea/client.go

@@ -433,49 +433,71 @@ func (c *Client) GetLabels(ctx context.Context, owner, repo string) ([]Label, er
 	return labels, nil
 }
 
+// @goal: WHOOSH-LABELS-004, WSH-CONSISTENCY - Ecosystem standardization
+// WHY: Ensures all CHORUS ecosystem repositories have consistent GitHub-standard labels
 // EnsureRequiredLabels ensures that required labels exist in the repository
 func (c *Client) EnsureRequiredLabels(ctx context.Context, owner, repo string) error {
+	// @goal: WHOOSH-LABELS-004 - Standardized label set matching WHOOSH repository conventions
+	// WHY: Provides consistent issue categorization across all CHORUS ecosystem repositories
 	requiredLabels := []CreateLabelRequest{
+		{
+			Name:        "bug",
+			Color:       "ee0701",
+			Description: "Something is not working",
+		},
 		{
 			Name:        "bzzz-task",
-			Color:       "ff6b6b",
-			Description: "Issues that should be converted to BZZZ tasks for CHORUS",
+			Color:       "5319e7", // @goal: WHOOSH-LABELS-004 - Corrected color to match ecosystem standard
+			Description: "CHORUS task for auto ingestion.",
 		},
 		{
-			Name:        "whoosh-monitored",
-			Color:       "4ecdc4", 
-			Description: "Repository is monitored by WHOOSH",
+			Name:        "duplicate",
+			Color:       "cccccc",
+			Description: "This issue or pull request already exists",
 		},
 		{
-			Name:        "priority-high",
-			Color:       "e74c3c",
-			Description: "High priority task for immediate attention",
+			Name:        "enhancement",
+			Color:       "84b6eb",
+			Description: "New feature",
 		},
 		{
-			Name:        "priority-medium",
-			Color:       "f39c12",
-			Description: "Medium priority task",
+			Name:        "help wanted",
+			Color:       "128a0c",
+			Description: "Need some help",
 		},
 		{
-			Name:        "priority-low",
-			Color:       "95a5a6",
-			Description: "Low priority task",
+			Name:        "invalid",
+			Color:       "e6e6e6",
+			Description: "Something is wrong",
+		},
+		{
+			Name:        "question",
+			Color:       "cc317c",
+			Description: "More information is needed",
+		},
+		{
+			Name:        "wontfix",
+			Color:       "ffffff",
+			Description: "This won't be fixed",
 		},
 	}
 	
-	// Get existing labels
+	// @goal: WHOOSH-LABELS-004 - Check existing labels to avoid duplicates
+	// WHY: Prevents API errors from attempting to create labels that already exist
 	existingLabels, err := c.GetLabels(ctx, owner, repo)
 	if err != nil {
 		return fmt.Errorf("failed to get existing labels: %w", err)
 	}
-	
-	// Create a map of existing label names for quick lookup
+
+	// @goal: WHOOSH-LABELS-004 - Build lookup map for efficient duplicate checking
+	// WHY: O(1) lookup performance for label existence checking
 	existingLabelNames := make(map[string]bool)
 	for _, label := range existingLabels {
 		existingLabelNames[label.Name] = true
 	}
-	
-	// Create missing required labels
+
+	// @goal: WHOOSH-LABELS-004 - Create only missing standardized labels
+	// WHY: Ensures all repositories have consistent labeling without overwriting existing labels
 	for _, requiredLabel := range requiredLabels {
 		if !existingLabelNames[requiredLabel.Name] {
 			_, err := c.CreateLabel(ctx, owner, repo, requiredLabel)

internal/server/server.go

@@ -2352,11 +2352,14 @@ func (s *Server) createRepositoryHandler(w http.ResponseWriter, r *http.Request)
 	}
 	
 	// Automatically create required labels in the Gitea repository
+	// @goal: WHOOSH-LABELS-004 - Automatic label creation on repository addition
+	// WHY: Ensures standardized ecosystem labels are available immediately for issue categorization
 	if req.SourceType == "gitea" && s.repoMonitor != nil && s.repoMonitor.GetGiteaClient() != nil {
 		log.Info().
 			Str("repository", fullName).
 			Msg("Creating required labels in Gitea repository")
-		
+
+		// @goal: WHOOSH-LABELS-004 - Apply standardized label set to new repository
 		err := s.repoMonitor.GetGiteaClient().EnsureRequiredLabels(context.Background(), req.Owner, req.Name)
 		if err != nil {
 			log.Warn().
@@ -2634,7 +2637,8 @@ func (s *Server) ensureRepositoryLabelsHandler(w http.ResponseWriter, r *http.Re
 		return
 	}
 	
-	// Ensure required labels exist
+	// @goal: WHOOSH-LABELS-004 - Manual label synchronization endpoint
+	// WHY: Allows updating existing repositories to standardized label set
 	err = s.repoMonitor.GetGiteaClient().EnsureRequiredLabels(context.Background(), owner, name)
 	if err != nil {
 		log.Error().