feat(crew): Provision .claude/commands/ for crew and polecat workspaces (gt-jhr85)

When adding a crew member with 'gt crew add' or spawning a polecat,
provision the .claude/commands/ directory with standard slash commands
like /handoff. This ensures all agents have Gas Town utilities even if
the source repo does not have them tracked.

Changes:
- Add embedded commands templates (internal/templates/commands/)
- Add ProvisionCommands() to templates package
- Call ProvisionCommands from crew and polecat managers
- Add gt doctor commands-provisioned check with --fix support

internal/templates/commands/handoff.md

@@ -0,0 +1,21 @@
+---
+description: Hand off to fresh session, work continues from hook
+allowed-tools: Bash(gt mail send:*),Bash(gt handoff:*)
+argument-hint: [message]
+---
+
+Hand off to a fresh session.
+
+User's handoff message (if any): $ARGUMENTS
+
+Execute these steps in order:
+
+1. If user provided a message, send handoff mail to yourself first.
+   Construct your mail address from your identity (e.g., gastown/crew/max for crew, mayor/ for mayor).
+   Example: `gt mail send gastown/crew/max -s "HANDOFF: Session cycling" -m "USER_MESSAGE_HERE"`
+
+2. Run the handoff command (this will respawn your session with a fresh Claude):
+   `gt handoff`
+
+Note: The new session will auto-prime via the SessionStart hook and find your handoff mail.
+End watch. A new session takes over, picking up any molecule on the hook.

internal/templates/templates.go

@@ -5,12 +5,17 @@ import (
 	"bytes"
 	"embed"
 	"fmt"
+	"os"
+	"path/filepath"
 	"text/template"
 )
 
 //go:embed roles/*.md.tmpl messages/*.md.tmpl
 var templateFS embed.FS
 
+//go:embed commands/*.md
+var commandsFS embed.FS
+
 // Templates manages role and message templates.
 type Templates struct {
 	roleTemplates    *template.Template
@@ -148,3 +153,90 @@ func GetAllRoleTemplates() (map[string][]byte, error) {
 
 	return result, nil
 }
+
+// ProvisionCommands creates the .claude/commands/ directory with standard slash commands.
+// This ensures crew/polecat workspaces have the handoff command and other utilities
+// even if the source repo doesn't have them tracked.
+// If a command already exists, it is skipped (no overwrite).
+func ProvisionCommands(workspacePath string) error {
+	entries, err := commandsFS.ReadDir("commands")
+	if err != nil {
+		return fmt.Errorf("reading commands directory: %w", err)
+	}
+
+	// Create .claude/commands/ directory
+	commandsDir := filepath.Join(workspacePath, ".claude", "commands")
+	if err := os.MkdirAll(commandsDir, 0755); err != nil {
+		return fmt.Errorf("creating commands directory: %w", err)
+	}
+
+	for _, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+
+		destPath := filepath.Join(commandsDir, entry.Name())
+
+		// Skip if command already exists (don't overwrite user customizations)
+		if _, err := os.Stat(destPath); err == nil {
+			continue
+		}
+
+		content, err := commandsFS.ReadFile("commands/" + entry.Name())
+		if err != nil {
+			return fmt.Errorf("reading %s: %w", entry.Name(), err)
+		}
+
+		if err := os.WriteFile(destPath, content, 0644); err != nil {
+			return fmt.Errorf("writing %s: %w", entry.Name(), err)
+		}
+	}
+
+	return nil
+}
+
+// CommandNames returns the list of embedded slash commands.
+func CommandNames() ([]string, error) {
+	entries, err := commandsFS.ReadDir("commands")
+	if err != nil {
+		return nil, fmt.Errorf("reading commands directory: %w", err)
+	}
+
+	var names []string
+	for _, entry := range entries {
+		if !entry.IsDir() {
+			names = append(names, entry.Name())
+		}
+	}
+	return names, nil
+}
+
+// HasCommands checks if a workspace has the .claude/commands/ directory provisioned.
+func HasCommands(workspacePath string) bool {
+	commandsDir := filepath.Join(workspacePath, ".claude", "commands")
+	info, err := os.Stat(commandsDir)
+	return err == nil && info.IsDir()
+}
+
+// MissingCommands returns the list of embedded commands missing from the workspace.
+func MissingCommands(workspacePath string) ([]string, error) {
+	entries, err := commandsFS.ReadDir("commands")
+	if err != nil {
+		return nil, fmt.Errorf("reading commands directory: %w", err)
+	}
+
+	commandsDir := filepath.Join(workspacePath, ".claude", "commands")
+	var missing []string
+
+	for _, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+		destPath := filepath.Join(commandsDir, entry.Name())
+		if _, err := os.Stat(destPath); os.IsNotExist(err) {
+			missing = append(missing, entry.Name())
+		}
+	}
+
+	return missing, nil
+}