feat: Add mol_type schema field for molecule type classification (bd-oxgi)

Add mol_type field to beads for swarm coordination:
- Values: 'swarm' (multi-polecat), 'patrol' (recurring ops), 'work' (default)
- Nullable, defaults to empty string (treated as 'work')

Changes:
- Add mol_type column to SQLite schema and migration 031
- Add MolType type with IsValid() validation in types.go
- Update insertIssue/GetIssue to handle mol_type
- Add --mol-type flag to create command
- Add mol_type filtering to list and ready commands
- Update RPC protocol for daemon mode support
- Update test schema in migrations_test.go

🤝 Generated with [Claude Code](https://claude.com/claude-code)

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

cmd/bd/list.go

@@ -356,6 +356,18 @@ var listCmd = &cobra.Command{
 		// Parent filtering
 		parentID, _ := cmd.Flags().GetString("parent")
 
+		// Molecule type filtering
+		molTypeStr, _ := cmd.Flags().GetString("mol-type")
+		var molType *types.MolType
+		if molTypeStr != "" {
+			mt := types.MolType(molTypeStr)
+			if !mt.IsValid() {
+				fmt.Fprintf(os.Stderr, "Error: invalid mol-type %q (must be swarm, patrol, or work)\n", molTypeStr)
+				os.Exit(1)
+			}
+			molType = &mt
+		}
+
 		// Pretty and watch flags (GH#654)
 		prettyFormat, _ := cmd.Flags().GetBool("pretty")
 		watchMode, _ := cmd.Flags().GetBool("watch")
@@ -533,6 +545,11 @@ var listCmd = &cobra.Command{
 			filter.ParentID = &parentID
 		}
 
+		// Molecule type filtering
+		if molType != nil {
+			filter.MolType = molType
+		}
+
 		// Check database freshness before reading
 		// Skip check when using daemon (daemon auto-imports on staleness)
 		ctx := rootCtx
@@ -906,6 +923,9 @@ func init() {
 	// Parent filtering: filter children by parent issue
 	listCmd.Flags().String("parent", "", "Filter by parent issue ID (shows children of specified issue)")
 
+	// Molecule type filtering
+	listCmd.Flags().String("mol-type", "", "Filter by molecule type: swarm, patrol, or work")
+
 	// Pretty and watch flags (GH#654)
 	listCmd.Flags().Bool("pretty", false, "Display issues in a tree format with status/priority symbols")
 	listCmd.Flags().BoolP("watch", "w", false, "Watch for changes and auto-update display (implies --pretty)")