feat(doctor): add rig identity beads check

Adds RigBeadsCheck to gt doctor to verify rig identity beads exist.
These beads track rig metadata (git URL, prefix, state) and are created
by gt rig add. The check scans routes.jsonl and verifies each rig
has an identity bead, with --fix to create missing ones.

Recovered from furiosa's uncommitted work after worker interruption.

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

internal/doctor/rig_beads_check.go

@@ -0,0 +1,171 @@
+package doctor
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+
+	"github.com/steveyegge/gastown/internal/beads"
+	"github.com/steveyegge/gastown/internal/rig"
+)
+
+// RigBeadsCheck verifies that rig identity beads exist for all rigs.
+// Rig identity beads track rig metadata like git URL, prefix, and operational state.
+// They are created by gt rig add (see gt-zmznh) but may be missing for legacy rigs.
+type RigBeadsCheck struct {
+	FixableCheck
+}
+
+// NewRigBeadsCheck creates a new rig identity beads check.
+func NewRigBeadsCheck() *RigBeadsCheck {
+	return &RigBeadsCheck{
+		FixableCheck: FixableCheck{
+			BaseCheck: BaseCheck{
+				CheckName:        "rig-beads-exist",
+				CheckDescription: "Verify rig identity beads exist for all rigs",
+			},
+		},
+	}
+}
+
+// Run checks if rig identity beads exist for all rigs.
+func (c *RigBeadsCheck) Run(ctx *CheckContext) *CheckResult {
+	// Load routes to get rig info
+	townBeadsDir := filepath.Join(ctx.TownRoot, ".beads")
+	routes, err := beads.LoadRoutes(townBeadsDir)
+	if err != nil {
+		return &CheckResult{
+			Name:    c.Name(),
+			Status:  StatusWarning,
+			Message: "Could not load routes.jsonl",
+		}
+	}
+
+	// Build unique rig list from routes
+	// Routes have format: prefix "gt-" -> path "gastown/mayor/rig"
+	rigSet := make(map[string]struct {
+		prefix    string
+		beadsPath string
+	})
+	for _, r := range routes {
+		// Extract rig name from path (first component)
+		parts := strings.Split(r.Path, "/")
+		if len(parts) >= 1 && parts[0] != "." {
+			rigName := parts[0]
+			prefix := strings.TrimSuffix(r.Prefix, "-")
+			if _, exists := rigSet[rigName]; !exists {
+				rigSet[rigName] = struct {
+					prefix    string
+					beadsPath string
+				}{
+					prefix:    prefix,
+					beadsPath: r.Path,
+				}
+			}
+		}
+	}
+
+	if len(rigSet) == 0 {
+		return &CheckResult{
+			Name:    c.Name(),
+			Status:  StatusOK,
+			Message: "No rigs to check",
+		}
+	}
+
+	var missing []string
+	var checked int
+
+	// Check each rig for its identity bead
+	for rigName, info := range rigSet {
+		rigBeadsPath := filepath.Join(ctx.TownRoot, info.beadsPath)
+		bd := beads.New(rigBeadsPath)
+
+		rigBeadID := beads.RigBeadIDWithPrefix(info.prefix, rigName)
+		if _, err := bd.Show(rigBeadID); err != nil {
+			missing = append(missing, rigBeadID)
+		}
+		checked++
+	}
+
+	if len(missing) == 0 {
+		return &CheckResult{
+			Name:    c.Name(),
+			Status:  StatusOK,
+			Message: fmt.Sprintf("All %d rig identity beads exist", checked),
+		}
+	}
+
+	return &CheckResult{
+		Name:    c.Name(),
+		Status:  StatusError,
+		Message: fmt.Sprintf("%d rig identity bead(s) missing", len(missing)),
+		Details: missing,
+		FixHint: "Run 'gt doctor --fix' to create missing rig identity beads",
+	}
+}
+
+// Fix creates missing rig identity beads.
+func (c *RigBeadsCheck) Fix(ctx *CheckContext) error {
+	// Load routes to get rig info
+	townBeadsDir := filepath.Join(ctx.TownRoot, ".beads")
+	routes, err := beads.LoadRoutes(townBeadsDir)
+	if err != nil {
+		return fmt.Errorf("loading routes.jsonl: %w", err)
+	}
+
+	// Build unique rig list from routes
+	rigSet := make(map[string]struct {
+		prefix    string
+		beadsPath string
+	})
+	for _, r := range routes {
+		parts := strings.Split(r.Path, "/")
+		if len(parts) >= 1 && parts[0] != "." {
+			rigName := parts[0]
+			prefix := strings.TrimSuffix(r.Prefix, "-")
+			if _, exists := rigSet[rigName]; !exists {
+				rigSet[rigName] = struct {
+					prefix    string
+					beadsPath string
+				}{
+					prefix:    prefix,
+					beadsPath: r.Path,
+				}
+			}
+		}
+	}
+
+	if len(rigSet) == 0 {
+		return nil // No rigs to process
+	}
+
+	// Create missing rig identity beads
+	for rigName, info := range rigSet {
+		rigBeadsPath := filepath.Join(ctx.TownRoot, info.beadsPath)
+		bd := beads.New(rigBeadsPath)
+
+		rigBeadID := beads.RigBeadIDWithPrefix(info.prefix, rigName)
+		if _, err := bd.Show(rigBeadID); err != nil {
+			// Bead doesn't exist - create it
+			// Try to get git URL from rig config
+			rigPath := filepath.Join(ctx.TownRoot, rigName)
+			gitURL := ""
+			if cfg, err := rig.LoadRigConfig(rigPath); err == nil {
+				gitURL = cfg.GitURL
+			}
+
+			fields := &beads.RigFields{
+				Repo:   gitURL,
+				Prefix: info.prefix,
+				State:  "active",
+			}
+
+			if _, err := bd.CreateRigBead(rigBeadID, rigName, fields); err != nil {
+				return fmt.Errorf("creating %s: %w", rigBeadID, err)
+			}
+		}
+	}
+
+	return nil
+}