feat: add .runtime/overlay/ support for polecat/crew worktrees

Add overlay directory support to automatically copy gitignored files
(like .env, config files) from <rig>/.runtime/overlay/ to polecat
and crew worktree roots when they are spawned.

This allows services started by polecats/crew to have their required
configuration files at the root without committing them to git.

Changes:
- Add copyOverlay() function to polecat and crew managers
- Call copyOverlay() after setupSharedBeads() in AddWithOptions/RepairWorktreeWithOptions
- Non-fatal: overlay copy failures only log warnings, don't block spawn

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

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

internal/crew/manager.go

@@ -174,6 +174,13 @@ func (m *Manager) Add(name string, createBranch bool) (*CrewWorker, error) {
 		fmt.Printf("Warning: could not set up shared beads: %v\n", err)
 	}
 
+	// Copy overlay files from .runtime/overlay/ to crew root.
+	// This allows services to have .env and other config files at their root.
+	if err := m.copyOverlay(crewPath); err != nil {
+		// Non-fatal - log warning but continue
+		fmt.Printf("Warning: could not copy overlay files: %v\n", err)
+	}
+
 	// NOTE: Slash commands (.claude/commands/) are provisioned at town level by gt install.
 	// All agents inherit them via Claude's directory traversal - no per-workspace copies needed.
 
@@ -570,3 +577,59 @@ func (m *Manager) IsRunning(name string) (bool, error) {
 	sessionID := m.SessionName(name)
 	return t.HasSession(sessionID)
 }
+
+// copyOverlay copies files from <rig>/.runtime/overlay/ to the crew worker root.
+// This allows storing gitignored files (like .env) that services need at their root.
+// The overlay is copied non-recursively - only files, not subdirectories.
+//
+// Structure:
+//
+//	rig/
+//	  .runtime/
+//	    overlay/
+//	      .env          <- Copied to crew root
+//	      config.json    <- Copied to crew root
+//	  crew/
+//	    <name>/
+//	      .env          <- Copied from overlay
+//	      config.json    <- Copied from overlay
+func (m *Manager) copyOverlay(crewPath string) error {
+	overlayDir := filepath.Join(m.rig.Path, ".runtime", "overlay")
+
+	// Check if overlay directory exists
+	entries, err := os.ReadDir(overlayDir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			// No overlay directory - not an error, just nothing to copy
+			return nil
+		}
+		return fmt.Errorf("reading overlay dir: %w", err)
+	}
+
+	// Copy each file (not directories) from overlay to crew root
+	for _, entry := range entries {
+		if entry.IsDir() {
+			// Skip subdirectories - only copy files at overlay root
+			continue
+		}
+
+		srcPath := filepath.Join(overlayDir, entry.Name())
+		dstPath := filepath.Join(crewPath, entry.Name())
+
+		// Read source file
+		data, err := os.ReadFile(srcPath)
+		if err != nil {
+			// Log warning but continue - don't fail spawn for overlay issues
+			fmt.Printf("Warning: could not read overlay file %s: %v\n", entry.Name(), err)
+			continue
+		}
+
+		// Write to destination
+		if err := os.WriteFile(dstPath, data, 0644); err != nil {
+			fmt.Printf("Warning: could not write overlay file %s: %v\n", entry.Name(), err)
+			continue
+		}
+	}
+
+	return nil
+}