crew at: don't link windows by default, add --detached flag

When running `gt crew at` from inside tmux:
- No longer auto-links the target session as a tab
- Just prints "Started X. Use C-b s to switch."
- User stays in their current pane

When running from outside tmux:
- Default: attach to the session (existing behavior)
- With -d/--detached: start session without attaching

This gives users more control over tmux session navigation and
reduces confusion for tmux newcomers.

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

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

internal/cmd/crew.go

@@ -6,13 +6,14 @@ import (
 
 // Crew command flags
 var (
-	crewRig     string
-	crewBranch  bool
-	crewJSON    bool
-	crewForce   bool
-	crewNoTmux  bool
-	crewMessage string
-	crewAccount string
+	crewRig      string
+	crewBranch   bool
+	crewJSON     bool
+	crewForce    bool
+	crewNoTmux   bool
+	crewDetached bool
+	crewMessage  string
+	crewAccount  string
 )
 
 var crewCmd = &cobra.Command{
@@ -79,6 +80,12 @@ var crewAtCmd = &cobra.Command{
 Creates a new tmux session if none exists, or attaches to existing.
 Use --no-tmux to just print the directory path instead.
 
+When run from inside tmux, the session is started but you stay in your
+current pane. Use C-b s to switch to the new session.
+
+When run from outside tmux, you are attached to the session (unless
+--detached is specified).
+
 Role Discovery:
   If no name is provided, attempts to detect the crew workspace from the
   current directory. If you're in <rig>/crew/<name>/, it will attach to
@@ -87,6 +94,7 @@ Role Discovery:
 Examples:
   gt crew at dave                 # Attach to dave's session
   gt crew at                      # Auto-detect from cwd
+  gt crew at dave --detached      # Start session without attaching
   gt crew at dave --no-tmux       # Just print path`,
 	Args: cobra.MaximumNArgs(1),
 	RunE: runCrewAt,
@@ -198,6 +206,7 @@ func init() {
 
 	crewAtCmd.Flags().StringVar(&crewRig, "rig", "", "Rig to use")
 	crewAtCmd.Flags().BoolVar(&crewNoTmux, "no-tmux", false, "Just print directory path")
+	crewAtCmd.Flags().BoolVarP(&crewDetached, "detached", "d", false, "Start session without attaching")
 	crewAtCmd.Flags().StringVar(&crewAccount, "account", "", "Claude Code account handle to use (overrides default)")
 
 	crewRemoveCmd.Flags().StringVar(&crewRig, "rig", "", "Rig to use")

internal/cmd/crew_at.go

@@ -160,6 +160,18 @@ func runCrewAt(cmd *cobra.Command, args []string) error {
 		return execClaude("gt prime")
 	}
 
-	// Attach to session using exec to properly forward TTY
+	// If inside tmux (but different session), don't switch - just inform user
+	if tmux.IsInsideTmux() {
+		fmt.Printf("Started %s/%s. Use C-b s to switch.\n", r.Name, name)
+		return nil
+	}
+
+	// Outside tmux: attach unless --detached flag is set
+	if crewDetached {
+		fmt.Printf("Started %s/%s. Run 'gt crew at %s' to attach.\n", r.Name, name, name)
+		return nil
+	}
+
+	// Attach to session
 	return attachToTmuxSession(sessionID)
 }

internal/cmd/crew_helpers.go

@@ -12,7 +12,6 @@ import (
 	"github.com/steveyegge/gastown/internal/git"
 	"github.com/steveyegge/gastown/internal/rig"
 	"github.com/steveyegge/gastown/internal/style"
-	"github.com/steveyegge/gastown/internal/tmux"
 	"github.com/steveyegge/gastown/internal/workspace"
 )
 
@@ -169,21 +168,9 @@ func isInTmuxSession(targetSession string) bool {
 	return currentSession == targetSession
 }
 
-// attachToTmuxSession attaches to a tmux session with smart behavior:
-// - If already inside tmux: links the session as a new tab (use C-b n/p to switch)
-// - If outside tmux: attaches normally (takes over terminal)
+// attachToTmuxSession attaches to a tmux session.
+// Should only be called from outside tmux.
 func attachToTmuxSession(sessionID string) error {
-	// If already inside tmux, link the window as a tab instead of switching sessions
-	if tmux.IsInsideTmux() {
-		t := tmux.NewTmux()
-		if err := t.LinkWindow(sessionID, 0); err != nil {
-			return fmt.Errorf("linking window: %w", err)
-		}
-		fmt.Printf("Linked %s as a new tab. Use C-b n to switch to it.\n", sessionID)
-		return nil
-	}
-
-	// Outside tmux: attach normally
 	tmuxPath, err := exec.LookPath("tmux")
 	if err != nil {
 		return fmt.Errorf("tmux not found: %w", err)