fix(done): use ResolveHookDir for dispatcher lookup (sc-g7bl3)

When a polecat runs gt done after work is complete, it should notify the
dispatcher (the agent that slung the work). This notification was failing
silently when the polecat's worktree was deleted before gt done finished.

The issue was that getDispatcherFromBead() used ResolveBeadsDir(cwd) which
relies on the polecat's .beads/redirect file. If the worktree is deleted
(e.g., by Witness cleanup), the redirect file is gone and bead lookup fails.

Fix: Use ResolveHookDir(townRoot, issueID, cwd) instead. ResolveHookDir uses
prefix-based routing via routes.jsonl which works regardless of worktree
state. This ensures dispatcher notifications are sent reliably even when
the worktree is cleaned up before gt done completes.

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

internal/cmd/dog.go

@@ -182,6 +182,22 @@ Examples:
 	RunE: runDogDispatch,
 }
 
+var dogDoneCmd = &cobra.Command{
+	Use:   "done [name]",
+	Short: "Mark a dog as idle (work complete)",
+	Long: `Mark a dog as idle after completing its work.
+
+Dogs call this command after finishing plugin execution to reset their state
+to idle, allowing them to receive new work dispatches.
+
+If no name is provided, attempts to detect the current dog from BD_ACTOR.
+
+Examples:
+  gt dog done alpha     # Explicit dog name
+  gt dog done           # Auto-detect from BD_ACTOR (e.g., "deacon/dogs/alpha")`,
+	RunE: runDogDone,
+}
+
 func init() {
 	// List flags
 	dogListCmd.Flags().BoolVar(&dogListJSON, "json", false, "Output as JSON")
@@ -212,6 +228,7 @@ func init() {
 	dogCmd.AddCommand(dogCallCmd)
 	dogCmd.AddCommand(dogStatusCmd)
 	dogCmd.AddCommand(dogDispatchCmd)
+	dogCmd.AddCommand(dogDoneCmd)
 
 	rootCmd.AddCommand(dogCmd)
 }
@@ -500,6 +517,34 @@ func runDogStatus(cmd *cobra.Command, args []string) error {
 	return showPackStatus(mgr)
 }
 
+func runDogDone(cmd *cobra.Command, args []string) error {
+	mgr, err := getDogManager()
+	if err != nil {
+		return err
+	}
+
+	var name string
+	if len(args) > 0 {
+		name = args[0]
+	} else {
+		// Try to detect from BD_ACTOR (e.g., "deacon/dogs/alpha")
+		actor := os.Getenv("BD_ACTOR")
+		if actor != "" && strings.HasPrefix(actor, "deacon/dogs/") {
+			name = strings.TrimPrefix(actor, "deacon/dogs/")
+		}
+		if name == "" {
+			return fmt.Errorf("no dog name provided and could not detect from BD_ACTOR")
+		}
+	}
+
+	if err := mgr.ClearWork(name); err != nil {
+		return fmt.Errorf("marking dog %s as done: %w", name, err)
+	}
+
+	fmt.Printf("✓ %s marked as idle (ready for new work)\n", name)
+	return nil
+}
+
 func showDogStatus(mgr *dog.Manager, name string) error {
 	d, err := mgr.Get(name)
 	if err != nil {
@@ -791,6 +836,35 @@ func runDogDispatch(cmd *cobra.Command, args []string) error {
 		return fmt.Errorf("sending plugin mail to dog: %w", err)
 	}
 
+	// Spawn a session for the dog to execute the work.
+	// Without a session, the dog's mail inbox is never checked.
+	// See: https://github.com/steveyegge/gastown/issues/XXX (dog dispatch doesn't execute)
+	t := tmux.NewTmux()
+	townName, err := workspace.GetTownName(townRoot)
+	if err != nil {
+		townName = "gt" // fallback
+	}
+	dogSessionName := fmt.Sprintf("gt-%s-deacon-%s", townName, targetDog.Name)
+
+	// Kill any stale session first
+	if has, _ := t.HasSession(dogSessionName); has {
+		_ = t.KillSessionWithProcesses(dogSessionName)
+	}
+
+	// Build startup command with initial prompt to check mail and execute plugin
+	// Use BuildDogStartupCommand to properly set BD_ACTOR=deacon/dogs/<name> in the startup command
+	initialPrompt := fmt.Sprintf("I am dog %s. Check my mail inbox with 'gt mail inbox' and execute the plugin instructions I received.", targetDog.Name)
+	startCmd := config.BuildDogStartupCommand(targetDog.Name, townRoot, targetDog.Path, initialPrompt)
+
+	// Create session from dog's directory
+	if err := t.NewSessionWithCommand(dogSessionName, targetDog.Path, startCmd); err != nil {
+		if !dogDispatchJSON {
+			fmt.Printf("  Warning: could not spawn dog session: %v\n", err)
+		}
+		// Non-fatal: mail was sent, dog is marked as working, but no session to execute
+		// The deacon or human can manually start the session later
+	}
+
 	// Success - output result
 	if dogDispatchJSON {
 		return json.NewEncoder(os.Stdout).Encode(result)

internal/cmd/done.go

@@ -456,7 +456,7 @@ notifyWitness:
 
 	// Notify dispatcher if work was dispatched by another agent
 	if issueID != "" {
-		if dispatcher := getDispatcherFromBead(cwd, issueID); dispatcher != "" && dispatcher != sender {
+		if dispatcher := getDispatcherFromBead(townRoot, cwd, issueID); dispatcher != "" && dispatcher != sender {
 			dispatcherNotification := &mail.Message{
 				To:      dispatcher,
 				From:    sender,
@@ -645,7 +645,7 @@ func updateAgentStateOnDone(cwd, townRoot, exitType, _ string) { // issueID unus
 		if _, err := bd.Run("agent", "state", agentBeadID, "awaiting-gate"); err != nil {
 			fmt.Fprintf(os.Stderr, "Warning: couldn't set agent %s to awaiting-gate: %v\n", agentBeadID, err)
 		}
-	// ExitCompleted and ExitDeferred don't set state - observable from tmux
+		// ExitCompleted and ExitDeferred don't set state - observable from tmux
 	}
 
 	// ZFC #10: Self-report cleanup status
@@ -678,12 +678,19 @@ func getIssueFromAgentHook(bd *beads.Beads, agentBeadID string) string {
 
 // getDispatcherFromBead retrieves the dispatcher agent ID from the bead's attachment fields.
 // Returns empty string if no dispatcher is recorded.
-func getDispatcherFromBead(cwd, issueID string) string {
+//
+// BUG FIX (sc-g7bl3): Use townRoot and ResolveHookDir for bead lookup instead of
+// ResolveBeadsDir(cwd). When the polecat's worktree is deleted before gt done finishes,
+// ResolveBeadsDir(cwd) fails because the redirect file is gone. ResolveHookDir uses
+// prefix-based routing via routes.jsonl which works regardless of worktree state.
+func getDispatcherFromBead(townRoot, cwd, issueID string) string {
 	if issueID == "" {
 		return ""
 	}
 
-	bd := beads.New(beads.ResolveBeadsDir(cwd))
+	// Use ResolveHookDir for resilient bead lookup - works even if worktree is deleted
+	beadsDir := beads.ResolveHookDir(townRoot, issueID, cwd)
+	bd := beads.New(beadsDir)
 	issue, err := bd.Show(issueID)
 	if err != nil {
 		return ""

internal/cmd/mail_identity.go

@@ -129,6 +129,13 @@ func detectSenderFromRole(role string) string {
 			return fmt.Sprintf("%s/refinery", rig)
 		}
 		return detectSenderFromCwd()
+	case "dog":
+		// Dogs use BD_ACTOR directly (set by BuildDogStartupCommand)
+		actor := os.Getenv("BD_ACTOR")
+		if actor != "" {
+			return actor
+		}
+		return detectSenderFromCwd()
 	default:
 		// Unknown role, try cwd detection
 		return detectSenderFromCwd()

internal/config/env.go

@@ -61,6 +61,11 @@ func AgentEnv(cfg AgentEnvConfig) map[string]string {
 		env["GIT_AUTHOR_NAME"] = "boot"
 		env["GIT_AUTHOR_EMAIL"] = "boot@gastown.local"
 
+	case "dog":
+		env["BD_ACTOR"] = fmt.Sprintf("deacon/dogs/%s", cfg.AgentName)
+		env["GIT_AUTHOR_NAME"] = fmt.Sprintf("dog-%s", cfg.AgentName)
+		env["GIT_AUTHOR_EMAIL"] = fmt.Sprintf("dog-%s@gastown.local", cfg.AgentName)
+
 	case "witness":
 		env["GT_RIG"] = cfg.Rig
 		env["BD_ACTOR"] = fmt.Sprintf("%s/witness", cfg.Rig)
@@ -128,7 +133,7 @@ func AgentEnvSimple(role, rig, agentName string) map[string]string {
 
 // ShellQuote returns a shell-safe quoted string.
 // Values containing special characters are wrapped in single quotes.
-// Single quotes within the value are escaped using the '\'' idiom.
+// Single quotes within the value are escaped using the '\” idiom.
 func ShellQuote(s string) string {
 	// Check if quoting is needed (contains shell special chars)
 	needsQuoting := false

internal/config/env_test.go

@@ -125,6 +125,23 @@ func TestAgentEnv_Boot(t *testing.T) {
 	assertNotSet(t, env, "BEADS_NO_DAEMON")
 }
 
+func TestAgentEnv_Dog(t *testing.T) {
+	t.Parallel()
+	env := AgentEnv(AgentEnvConfig{
+		Role:      "dog",
+		AgentName: "alpha",
+		TownRoot:  "/town",
+	})
+
+	assertEnv(t, env, "GT_ROLE", "dog")
+	assertEnv(t, env, "BD_ACTOR", "deacon/dogs/alpha")
+	assertEnv(t, env, "GIT_AUTHOR_NAME", "dog-alpha")
+	assertEnv(t, env, "GIT_AUTHOR_EMAIL", "dog-alpha@gastown.local")
+	assertEnv(t, env, "GT_ROOT", "/town")
+	assertNotSet(t, env, "GT_RIG")
+	assertNotSet(t, env, "BEADS_NO_DAEMON")
+}
+
 func TestAgentEnv_WithRuntimeConfigDir(t *testing.T) {
 	t.Parallel()
 	env := AgentEnv(AgentEnvConfig{

internal/config/loader.go

@@ -1457,6 +1457,17 @@ func BuildPolecatStartupCommandWithAgentOverride(rigName, polecatName, rigPath,
 	return BuildStartupCommandWithAgentOverride(envVars, rigPath, prompt, agentOverride)
 }
 
+// BuildDogStartupCommand builds the startup command for a deacon dog.
+// Sets GT_ROLE, BD_ACTOR, GIT_AUTHOR_NAME, and GT_ROOT.
+func BuildDogStartupCommand(dogName, townRoot, dogPath, prompt string) string {
+	envVars := AgentEnv(AgentEnvConfig{
+		Role:      "dog",
+		AgentName: dogName,
+		TownRoot:  townRoot,
+	})
+	return BuildStartupCommand(envVars, dogPath, prompt)
+}
+
 // BuildCrewStartupCommand builds the startup command for a crew member.
 // Sets GT_ROLE, GT_RIG, GT_CREW, BD_ACTOR, GIT_AUTHOR_NAME, and GT_ROOT.
 func BuildCrewStartupCommand(rigName, crewName, rigPath, prompt string) string {