docs: comprehensive hook/sling/handoff/nudge audit

- Update propulsion-principle.md: implementation status now accurate
- Update beads-data-plane.md: correct command syntax
- Fix hook.go: clarify durability semantics, add related commands
- Fix sling.go: use reliable NudgePane instead of raw tmux send-keys
- Add tmux.NudgePane: pane-targeted reliable message delivery

The command menagerie:
  gt hook    = assign (durability)
  gt nudge   = communicate (generic messaging)
  gt sling   = hook + nudge "start working"
  gt handoff = hook + restart (GUPP kicks in)

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

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

internal/cmd/hook.go

@@ -16,12 +16,13 @@ var hookCmd = &cobra.Command{
 	Short: "Attach work to your hook (durable across restarts)",
 	Long: `Attach a bead (issue) to your hook for durable work tracking.
 
-The hook is a lightweight, ephemeral attachment point. When you restart
-(via gt handoff), your SessionStart hook finds the slung work and you
-continue from where you left off.
+The hook is the "durability primitive" - work on your hook survives session
+restarts, context compaction, and handoffs. When you restart (via gt handoff),
+your SessionStart hook finds the attached work and you continue from where
+you left off.
 
-This is the "durability primitive" - work on your hook survives session
-restarts. For the full restart-and-resume flow, use: gt handoff <bead>
+This is "assign without action" - use gt sling to also start immediately,
+or gt handoff to hook and restart with fresh context.
 
 Examples:
   gt hook gt-abc                    # Attach issue gt-abc to your hook
@@ -30,8 +31,9 @@ Examples:
 
 Related commands:
   gt mol status      # See what's on your hook
-  gt handoff <bead>  # Hook + restart in one step
-  gt handoff         # Restart (uses existing hook if present)`,
+  gt sling <bead>    # Hook + start now (keep context)
+  gt handoff <bead>  # Hook + restart (fresh context)
+  gt nudge <agent>   # Send message to trigger execution`,
 	Args: cobra.ExactArgs(1),
 	RunE: runHook,
 }

internal/cmd/sling.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/spf13/cobra"
 	"github.com/steveyegge/gastown/internal/style"
+	"github.com/steveyegge/gastown/internal/tmux"
 	"github.com/steveyegge/gastown/internal/wisp"
 )
 
@@ -134,6 +135,7 @@ func runSling(cmd *cobra.Command, args []string) error {
 }
 
 // injectStartPrompt sends a prompt to the target pane to start working.
+// Uses the reliable nudge pattern: literal mode + 500ms debounce + separate Enter.
 func injectStartPrompt(pane, beadID, subject string) error {
 	if pane == "" {
 		return fmt.Errorf("no target pane")
@@ -147,9 +149,9 @@ func injectStartPrompt(pane, beadID, subject string) error {
 		prompt = fmt.Sprintf("Work slung: %s. Start working on it now - run `gt mol status` to see the hook, then begin.", beadID)
 	}
 
-	// Use tmux send-keys to inject the prompt
-	// Add Enter to submit it
-	return exec.Command("tmux", "send-keys", "-t", pane, prompt, "Enter").Run()
+	// Use the reliable nudge pattern (same as gt nudge / tmux.NudgeSession)
+	t := tmux.NewTmux()
+	return t.NudgePane(pane, prompt)
 }
 
 // resolveTargetAgent converts a target spec to agent ID and pane.

internal/tmux/tmux.go

@@ -207,6 +207,25 @@ func (t *Tmux) NudgeSession(session, message string) error {
 	return nil
 }
 
+// NudgePane sends a message to a specific pane reliably.
+// Same pattern as NudgeSession but targets a pane ID (e.g., "%9") instead of session name.
+func (t *Tmux) NudgePane(pane, message string) error {
+	// 1. Send text in literal mode (handles special characters)
+	if _, err := t.run("send-keys", "-t", pane, "-l", message); err != nil {
+		return err
+	}
+
+	// 2. Wait 500ms for paste to complete (tested, required)
+	time.Sleep(500 * time.Millisecond)
+
+	// 3. Send Enter as separate command (key to reliability)
+	if _, err := t.run("send-keys", "-t", pane, "Enter"); err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // GetPaneCommand returns the current command running in a pane.
 // Returns "bash", "zsh", "claude", "node", etc.
 func (t *Tmux) GetPaneCommand(session string) (string, error) {