feat(tmux): add per-rig color themes and dynamic status line (gt-vc1n)

Add tmux status bar theming for Gas Town sessions:

- Per-rig color themes auto-assigned via consistent hashing
- 10 curated dark themes (ocean, forest, rust, plum, etc.)
- Special gold/dark theme for Mayor
- Dynamic status line showing current issue and mail count
- Mayor status shows polecat/rig counts

New commands:
- gt theme --list: show available themes
- gt theme apply: apply to running sessions
- gt issue set/clear: agents update their current issue
- gt status-line: internal command for tmux refresh

Status bar format:
- Left: [rig/worker] role
- Right: <issue> | <mail> | HH:MM

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

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

internal/cmd/crew.go

@@ -504,6 +504,10 @@ func runCrewAt(cmd *cobra.Command, args []string) error {
 		_ = t.SetEnvironment(sessionID, "GT_RIG", r.Name)
 		_ = t.SetEnvironment(sessionID, "GT_CREW", name)
 
+		// Apply theme
+		theme := tmux.AssignTheme(r.Name)
+		_ = t.ConfigureGasTownSession(sessionID, theme, r.Name, name, "crew")
+
 		// Start claude with skip permissions (crew workers are trusted like Mayor)
 		// Use SendKeysDelayed to allow shell initialization after NewSession
 		if err := t.SendKeysDelayed(sessionID, "claude --dangerously-skip-permissions", 200); err != nil {
@@ -726,6 +730,10 @@ func runCrewRefresh(cmd *cobra.Command, args []string) error {
 	_ = t.SetEnvironment(sessionID, "GT_RIG", r.Name)
 	_ = t.SetEnvironment(sessionID, "GT_CREW", name)
 
+	// Apply theme
+	theme := tmux.AssignTheme(r.Name)
+	_ = t.ConfigureGasTownSession(sessionID, theme, r.Name, name, "crew")
+
 	// Start claude
 	// Use SendKeysDelayed to allow shell initialization after NewSession
 	if err := t.SendKeysDelayed(sessionID, "claude", 200); err != nil {
@@ -776,6 +784,10 @@ func runCrewRestart(cmd *cobra.Command, args []string) error {
 	t.SetEnvironment(sessionID, "GT_RIG", r.Name)
 	t.SetEnvironment(sessionID, "GT_CREW", name)
 
+	// Apply theme
+	theme := tmux.AssignTheme(r.Name)
+	_ = t.ConfigureGasTownSession(sessionID, theme, r.Name, name, "crew")
+
 	// Start claude with skip permissions (crew workers are trusted)
 	// Use SendKeysDelayed to allow shell initialization after NewSession
 	if err := t.SendKeysDelayed(sessionID, "claude --dangerously-skip-permissions", 200); err != nil {

internal/cmd/issue.go

@@ -0,0 +1,128 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"github.com/steveyegge/gastown/internal/tmux"
+)
+
+var issueCmd = &cobra.Command{
+	Use:   "issue",
+	Short: "Manage current issue for status line display",
+}
+
+var issueSetCmd = &cobra.Command{
+	Use:   "set <issue-id>",
+	Short: "Set the current issue (shown in tmux status line)",
+	Args:  cobra.ExactArgs(1),
+	RunE:  runIssueSet,
+}
+
+var issueClearCmd = &cobra.Command{
+	Use:   "clear",
+	Short: "Clear the current issue from status line",
+	RunE:  runIssueClear,
+}
+
+var issueShowCmd = &cobra.Command{
+	Use:   "show",
+	Short: "Show the current issue",
+	RunE:  runIssueShow,
+}
+
+func init() {
+	rootCmd.AddCommand(issueCmd)
+	issueCmd.AddCommand(issueSetCmd)
+	issueCmd.AddCommand(issueClearCmd)
+	issueCmd.AddCommand(issueShowCmd)
+}
+
+func runIssueSet(cmd *cobra.Command, args []string) error {
+	issueID := args[0]
+
+	// Get current tmux session
+	session := os.Getenv("TMUX_PANE")
+	if session == "" {
+		// Try to detect from GT env vars
+		session = detectCurrentSession()
+		if session == "" {
+			return fmt.Errorf("not in a tmux session")
+		}
+	}
+
+	t := tmux.NewTmux()
+	if err := t.SetEnvironment(session, "GT_ISSUE", issueID); err != nil {
+		return fmt.Errorf("setting issue: %w", err)
+	}
+
+	fmt.Printf("Issue set to: %s\n", issueID)
+	return nil
+}
+
+func runIssueClear(cmd *cobra.Command, args []string) error {
+	session := os.Getenv("TMUX_PANE")
+	if session == "" {
+		session = detectCurrentSession()
+		if session == "" {
+			return fmt.Errorf("not in a tmux session")
+		}
+	}
+
+	t := tmux.NewTmux()
+	// Set to empty string to clear
+	if err := t.SetEnvironment(session, "GT_ISSUE", ""); err != nil {
+		return fmt.Errorf("clearing issue: %w", err)
+	}
+
+	fmt.Println("Issue cleared")
+	return nil
+}
+
+func runIssueShow(cmd *cobra.Command, args []string) error {
+	session := os.Getenv("TMUX_PANE")
+	if session == "" {
+		session = detectCurrentSession()
+		if session == "" {
+			return fmt.Errorf("not in a tmux session")
+		}
+	}
+
+	t := tmux.NewTmux()
+	issue, err := t.GetEnvironment(session, "GT_ISSUE")
+	if err != nil {
+		return fmt.Errorf("getting issue: %w", err)
+	}
+
+	if issue == "" {
+		fmt.Println("No issue set")
+	} else {
+		fmt.Printf("Current issue: %s\n", issue)
+	}
+	return nil
+}
+
+// detectCurrentSession tries to find the tmux session name from env.
+func detectCurrentSession() string {
+	// Try to build session name from GT env vars
+	rig := os.Getenv("GT_RIG")
+	polecat := os.Getenv("GT_POLECAT")
+	crew := os.Getenv("GT_CREW")
+
+	if rig != "" {
+		if polecat != "" {
+			return fmt.Sprintf("gt-%s-%s", rig, polecat)
+		}
+		if crew != "" {
+			return fmt.Sprintf("gt-%s-crew-%s", rig, crew)
+		}
+	}
+
+	// Check if we're mayor
+	if os.Getenv("GT_ROLE") == "mayor" {
+		return "gt-mayor"
+	}
+
+	return ""
+}

internal/cmd/mayor.go

@@ -122,6 +122,10 @@ func startMayorSession(t *tmux.Tmux) error {
 	// Set environment
 	_ = t.SetEnvironment(MayorSessionName, "GT_ROLE", "mayor")
 
+	// Apply Mayor theme
+	theme := tmux.MayorTheme()
+	_ = t.ConfigureGasTownSession(MayorSessionName, theme, "", "Mayor", "coordinator")
+
 	// Launch Claude in a respawn loop - session survives restarts
 	// The startup hook handles 'gt prime' automatically
 	// Use SendKeysDelayed to allow shell initialization after NewSession

internal/cmd/statusline.go

@@ -0,0 +1,145 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/steveyegge/gastown/internal/mail"
+	"github.com/steveyegge/gastown/internal/tmux"
+)
+
+var (
+	statusLineSession string
+)
+
+var statusLineCmd = &cobra.Command{
+	Use:    "status-line",
+	Short:  "Output status line content for tmux (internal use)",
+	Hidden: true, // Internal command called by tmux
+	RunE:   runStatusLine,
+}
+
+func init() {
+	rootCmd.AddCommand(statusLineCmd)
+	statusLineCmd.Flags().StringVar(&statusLineSession, "session", "", "Tmux session name")
+}
+
+func runStatusLine(cmd *cobra.Command, args []string) error {
+	t := tmux.NewTmux()
+
+	// Get session environment
+	var rigName, polecat, crew, issue, role string
+
+	if statusLineSession != "" {
+		rigName, _ = t.GetEnvironment(statusLineSession, "GT_RIG")
+		polecat, _ = t.GetEnvironment(statusLineSession, "GT_POLECAT")
+		crew, _ = t.GetEnvironment(statusLineSession, "GT_CREW")
+		issue, _ = t.GetEnvironment(statusLineSession, "GT_ISSUE")
+		role, _ = t.GetEnvironment(statusLineSession, "GT_ROLE")
+	} else {
+		// Fallback to process environment
+		rigName = os.Getenv("GT_RIG")
+		polecat = os.Getenv("GT_POLECAT")
+		crew = os.Getenv("GT_CREW")
+		issue = os.Getenv("GT_ISSUE")
+		role = os.Getenv("GT_ROLE")
+	}
+
+	// Determine identity and output based on role
+	if role == "mayor" || statusLineSession == "gt-mayor" {
+		return runMayorStatusLine(t)
+	}
+
+	// Build mail identity
+	var identity string
+	if rigName != "" {
+		if polecat != "" {
+			identity = fmt.Sprintf("%s/%s", rigName, polecat)
+		} else if crew != "" {
+			identity = fmt.Sprintf("%s/%s", rigName, crew)
+		}
+	}
+
+	// Build status parts
+	var parts []string
+
+	// Current issue
+	if issue != "" {
+		parts = append(parts, issue)
+	}
+
+	// Mail count
+	if identity != "" {
+		unread := getUnreadMailCount(identity)
+		if unread > 0 {
+			parts = append(parts, fmt.Sprintf("\U0001F4EC %d", unread)) // mail emoji
+		}
+	}
+
+	// Output
+	if len(parts) > 0 {
+		fmt.Print(strings.Join(parts, " | ") + " |")
+	}
+
+	return nil
+}
+
+func runMayorStatusLine(t *tmux.Tmux) error {
+	// Count active sessions by listing tmux sessions
+	sessions, err := t.ListSessions()
+	if err != nil {
+		return nil // Silent fail
+	}
+
+	// Count gt-* sessions (polecats) and rigs
+	polecatCount := 0
+	rigs := make(map[string]bool)
+	for _, s := range sessions {
+		if strings.HasPrefix(s, "gt-") && s != "gt-mayor" {
+			polecatCount++
+			// Extract rig name: gt-<rig>-<worker>
+			parts := strings.SplitN(s, "-", 3)
+			if len(parts) >= 2 {
+				rigs[parts[1]] = true
+			}
+		}
+	}
+	rigCount := len(rigs)
+
+	// Get mayor mail
+	unread := getUnreadMailCount("mayor/")
+
+	// Build status
+	var parts []string
+	parts = append(parts, fmt.Sprintf("%d polecats", polecatCount))
+	parts = append(parts, fmt.Sprintf("%d rigs", rigCount))
+	if unread > 0 {
+		parts = append(parts, fmt.Sprintf("\U0001F4EC %d", unread))
+	}
+
+	fmt.Print(strings.Join(parts, " | ") + " |")
+	return nil
+}
+
+// getUnreadMailCount returns unread mail count for an identity.
+// Fast path - returns 0 on any error.
+func getUnreadMailCount(identity string) int {
+	// Find workspace
+	workDir, err := findBeadsWorkDir()
+	if err != nil {
+		return 0
+	}
+
+	// Create mailbox using beads
+	mailbox := mail.NewMailboxBeads(identity, workDir)
+
+	// Get count
+	_, unread, err := mailbox.Count()
+	if err != nil {
+		return 0
+	}
+
+	return unread
+}

internal/cmd/theme.go

@@ -0,0 +1,193 @@
+package cmd
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/steveyegge/gastown/internal/tmux"
+)
+
+var (
+	themeListFlag  bool
+	themeApplyFlag bool
+)
+
+var themeCmd = &cobra.Command{
+	Use:   "theme [name]",
+	Short: "View or set tmux theme for the current rig",
+	Long: `Manage tmux status bar themes for Gas Town sessions.
+
+Without arguments, shows the current theme assignment.
+With a name argument, sets the theme for this rig.
+
+Examples:
+  gt theme              # Show current theme
+  gt theme --list       # List available themes
+  gt theme forest       # Set theme to 'forest'
+  gt theme apply        # Apply theme to all running sessions in this rig`,
+	RunE: runTheme,
+}
+
+var themeApplyCmd = &cobra.Command{
+	Use:   "apply",
+	Short: "Apply theme to all running sessions in this rig",
+	RunE:  runThemeApply,
+}
+
+func init() {
+	rootCmd.AddCommand(themeCmd)
+	themeCmd.AddCommand(themeApplyCmd)
+	themeCmd.Flags().BoolVarP(&themeListFlag, "list", "l", false, "List available themes")
+}
+
+func runTheme(cmd *cobra.Command, args []string) error {
+	// List mode
+	if themeListFlag {
+		fmt.Println("Available themes:")
+		for _, name := range tmux.ListThemeNames() {
+			theme := tmux.GetThemeByName(name)
+			fmt.Printf("  %-10s  %s\n", name, theme.Style())
+		}
+		// Also show Mayor theme
+		mayor := tmux.MayorTheme()
+		fmt.Printf("  %-10s  %s (Mayor only)\n", mayor.Name, mayor.Style())
+		return nil
+	}
+
+	// Determine current rig
+	rigName := detectCurrentRig()
+	if rigName == "" {
+		rigName = "unknown"
+	}
+
+	// Show current theme assignment
+	if len(args) == 0 {
+		theme := tmux.AssignTheme(rigName)
+		fmt.Printf("Rig: %s\n", rigName)
+		fmt.Printf("Theme: %s (%s)\n", theme.Name, theme.Style())
+		return nil
+	}
+
+	// Set theme
+	themeName := args[0]
+	theme := tmux.GetThemeByName(themeName)
+	if theme == nil {
+		return fmt.Errorf("unknown theme: %s (use --list to see available themes)", themeName)
+	}
+
+	// TODO: Save to rig config.json
+	fmt.Printf("Theme '%s' selected for rig '%s'\n", themeName, rigName)
+	fmt.Println("Note: Run 'gt theme apply' to apply to running sessions")
+	fmt.Println("(Persistent config not yet implemented)")
+
+	return nil
+}
+
+func runThemeApply(cmd *cobra.Command, args []string) error {
+	t := tmux.NewTmux()
+
+	// Get all sessions
+	sessions, err := t.ListSessions()
+	if err != nil {
+		return fmt.Errorf("listing sessions: %w", err)
+	}
+
+	// Determine current rig
+	rigName := detectCurrentRig()
+
+	// Apply to matching sessions
+	applied := 0
+	for _, session := range sessions {
+		if !strings.HasPrefix(session, "gt-") {
+			continue
+		}
+
+		// Determine theme and identity for this session
+		var theme tmux.Theme
+		var rig, worker, role string
+
+		if session == "gt-mayor" {
+			theme = tmux.MayorTheme()
+			worker = "Mayor"
+			role = "coordinator"
+		} else {
+			// Parse session name: gt-<rig>-<worker> or gt-<rig>-crew-<name>
+			parts := strings.SplitN(session, "-", 3)
+			if len(parts) < 3 {
+				continue
+			}
+			rig = parts[1]
+
+			// Skip if not matching current rig (if we know it)
+			if rigName != "" && rig != rigName {
+				continue
+			}
+
+			workerPart := parts[2]
+			if strings.HasPrefix(workerPart, "crew-") {
+				worker = strings.TrimPrefix(workerPart, "crew-")
+				role = "crew"
+			} else {
+				worker = workerPart
+				role = "polecat"
+			}
+
+			theme = tmux.AssignTheme(rig)
+		}
+
+		// Apply theme and status format
+		if err := t.ApplyTheme(session, theme); err != nil {
+			fmt.Printf("  %s: failed (%v)\n", session, err)
+			continue
+		}
+		if err := t.SetStatusFormat(session, rig, worker, role); err != nil {
+			fmt.Printf("  %s: failed to set format (%v)\n", session, err)
+			continue
+		}
+		if err := t.SetDynamicStatus(session); err != nil {
+			fmt.Printf("  %s: failed to set dynamic status (%v)\n", session, err)
+			continue
+		}
+
+		fmt.Printf("  %s: applied %s theme\n", session, theme.Name)
+		applied++
+	}
+
+	if applied == 0 {
+		fmt.Println("No matching sessions found")
+	} else {
+		fmt.Printf("\nApplied theme to %d session(s)\n", applied)
+	}
+
+	return nil
+}
+
+// detectCurrentRig determines the rig from environment or cwd.
+func detectCurrentRig() string {
+	// Try environment first
+	if rig := detectCurrentSession(); rig != "" {
+		// Extract rig from session name
+		parts := strings.SplitN(rig, "-", 3)
+		if len(parts) >= 2 && parts[0] == "gt" {
+			return parts[1]
+		}
+	}
+
+	// Try to detect from cwd
+	cwd, err := findBeadsWorkDir()
+	if err != nil {
+		return ""
+	}
+
+	// Extract rig name from path
+	// Typical paths: /Users/stevey/gt/<rig>/...
+	parts := strings.Split(cwd, "/")
+	for i, p := range parts {
+		if p == "gt" && i+1 < len(parts) {
+			return parts[i+1]
+		}
+	}
+
+	return ""
+}

internal/cmd/witness.go

@@ -266,6 +266,10 @@ func runWitnessAttach(cmd *cobra.Command, args []string) error {
 		t.SetEnvironment(sessionName, "GT_ROLE", "witness")
 		t.SetEnvironment(sessionName, "GT_RIG", rigName)
 
+		// Apply theme (same as rig polecats)
+		theme := tmux.AssignTheme(rigName)
+		_ = t.ConfigureGasTownSession(sessionName, theme, rigName, "witness", "witness")
+
 		// Launch Claude in a respawn loop
 		loopCmd := `while true; do echo "👁️ Starting Witness for ` + rigName + `..."; claude --dangerously-skip-permissions; echo ""; echo "Witness exited. Restarting in 2s... (Ctrl-C to stop)"; sleep 2; done`
 		if err := t.SendKeysDelayed(sessionName, loopCmd, 200); err != nil {