feat(templates): Add local override support for role templates

Adds ability to override embedded role templates at town or rig level:
- Town: <townRoot>/templates/roles/<role>.md.tmpl
- Rig: <rigPath>/templates/roles/<role>.md.tmpl

Rig-level overrides take precedence over town-level.

This enables customizing polecat (or other role) behavior per-rig without
modifying gastown source, following the same 3-tier override pattern as
role configs.

New APIs:
- NewWithOverrides(townRoot, rigPath string) - loads templates with overrides
- HasRoleOverride(role string) bool - check if role has override
- RoleOverrideCount() int - count of loaded overrides

Implements sc-6ghhn

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/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/cmd/prime_output.go

@@ -18,8 +18,14 @@ import (
 
 // outputPrimeContext outputs the role-specific context using templates or fallback.
 func outputPrimeContext(ctx RoleContext) error {
-	// Try to use templates first
-	tmpl, err := templates.New()
+	// Calculate rig path for template overrides
+	var rigPath string
+	if ctx.Rig != "" && ctx.TownRoot != "" {
+		rigPath = filepath.Join(ctx.TownRoot, ctx.Rig)
+	}
+
+	// Try to use templates with override support
+	tmpl, err := templates.NewWithOverrides(ctx.TownRoot, rigPath)
 	if err != nil {
 		// Fall back to hardcoded output if templates fail
 		return outputPrimeContextFallback(ctx)

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 {

internal/templates/templates.go

@@ -20,6 +20,9 @@ var commandsFS embed.FS
 type Templates struct {
 	roleTemplates    *template.Template
 	messageTemplates *template.Template
+	// roleOverrides maps role name to override template content.
+	// When set, these are used instead of embedded templates.
+	roleOverrides map[string]*template.Template
 }
 
 // RoleData contains information for rendering role contexts.
@@ -81,11 +84,24 @@ type HandoffData struct {
 	GitDirty    bool
 }
 
-// New creates a new Templates instance.
+// New creates a new Templates instance with only embedded templates.
 func New() (*Templates, error) {
-	t := &Templates{}
+	return NewWithOverrides("", "")
+}
 
-	// Parse role templates
+// NewWithOverrides creates a Templates instance that checks for local overrides.
+// Override resolution order (later overrides earlier):
+//  1. Built-in templates (embedded in binary)
+//  2. Town-level overrides (<townRoot>/templates/roles/<role>.md.tmpl)
+//  3. Rig-level overrides (<rigPath>/templates/roles/<role>.md.tmpl)
+//
+// If townRoot or rigPath is empty, that level is skipped.
+func NewWithOverrides(townRoot, rigPath string) (*Templates, error) {
+	t := &Templates{
+		roleOverrides: make(map[string]*template.Template),
+	}
+
+	// Parse embedded role templates
 	roleTempl, err := template.ParseFS(templateFS, "roles/*.md.tmpl")
 	if err != nil {
 		return nil, fmt.Errorf("parsing role templates: %w", err)
@@ -99,14 +115,51 @@ func New() (*Templates, error) {
 	}
 	t.messageTemplates = msgTempl
 
+	// Load role overrides from filesystem
+	// Check both town and rig levels, rig takes precedence
+	roles := []string{"mayor", "witness", "refinery", "polecat", "crew", "deacon"}
+	overridePaths := []string{}
+	if townRoot != "" {
+		overridePaths = append(overridePaths, filepath.Join(townRoot, "templates", "roles"))
+	}
+	if rigPath != "" {
+		overridePaths = append(overridePaths, filepath.Join(rigPath, "templates", "roles"))
+	}
+
+	for _, role := range roles {
+		templateName := role + ".md.tmpl"
+		// Check each override path in order (later paths override earlier)
+		for _, overrideDir := range overridePaths {
+			overridePath := filepath.Join(overrideDir, templateName)
+			if content, err := os.ReadFile(overridePath); err == nil {
+				tmpl, err := template.New(templateName).Parse(string(content))
+				if err != nil {
+					return nil, fmt.Errorf("parsing override template %s: %w", overridePath, err)
+				}
+				t.roleOverrides[role] = tmpl
+			}
+		}
+	}
+
 	return t, nil
 }
 
 // RenderRole renders a role context template.
+// If an override template exists for the role, it is used instead of the embedded template.
 func (t *Templates) RenderRole(role string, data RoleData) (string, error) {
 	templateName := role + ".md.tmpl"
 
 	var buf bytes.Buffer
+
+	// Check for override template first
+	if override, ok := t.roleOverrides[role]; ok {
+		if err := override.Execute(&buf, data); err != nil {
+			return "", fmt.Errorf("rendering override template %s: %w", templateName, err)
+		}
+		return buf.String(), nil
+	}
+
+	// Fall back to embedded template
 	if err := t.roleTemplates.ExecuteTemplate(&buf, templateName, data); err != nil {
 		return "", fmt.Errorf("rendering role template %s: %w", templateName, err)
 	}
@@ -131,6 +184,17 @@ func (t *Templates) RoleNames() []string {
 	return []string{"mayor", "witness", "refinery", "polecat", "crew", "deacon"}
 }
 
+// HasRoleOverride returns true if the given role has a local override template.
+func (t *Templates) HasRoleOverride(role string) bool {
+	_, ok := t.roleOverrides[role]
+	return ok
+}
+
+// RoleOverrideCount returns the number of role templates that have local overrides.
+func (t *Templates) RoleOverrideCount() int {
+	return len(t.roleOverrides)
+}
+
 // MessageNames returns the list of available message templates.
 func (t *Templates) MessageNames() []string {
 	return []string{"spawn", "nudge", "escalation", "handoff"}

internal/templates/templates_test.go

@@ -1,6 +1,7 @@
 package templates
 
 import (
+	"os"
 	"strings"
 	"testing"
 )
@@ -295,3 +296,164 @@ func TestGetAllRoleTemplates_ContentValidity(t *testing.T) {
 		}
 	}
 }
+
+func TestNewWithOverrides_NoOverrides(t *testing.T) {
+	// When no override paths exist, should work like New()
+	tmpl, err := NewWithOverrides("/nonexistent/town", "/nonexistent/rig")
+	if err != nil {
+		t.Fatalf("NewWithOverrides() error = %v", err)
+	}
+	if tmpl == nil {
+		t.Fatal("NewWithOverrides() returned nil")
+	}
+
+	// Should have no overrides
+	if tmpl.RoleOverrideCount() != 0 {
+		t.Errorf("RoleOverrideCount() = %d, want 0", tmpl.RoleOverrideCount())
+	}
+
+	// Should still render embedded templates
+	data := RoleData{
+		Role:    "polecat",
+		RigName: "myrig",
+		Polecat: "TestCat",
+	}
+	output, err := tmpl.RenderRole("polecat", data)
+	if err != nil {
+		t.Fatalf("RenderRole() error = %v", err)
+	}
+	if !strings.Contains(output, "Polecat Context") {
+		t.Error("embedded template not rendered correctly")
+	}
+}
+
+func TestNewWithOverrides_WithOverride(t *testing.T) {
+	// Create a temp directory with an override template
+	tempDir := t.TempDir()
+	overrideDir := tempDir + "/templates/roles"
+	if err := os.MkdirAll(overrideDir, 0755); err != nil {
+		t.Fatalf("failed to create override dir: %v", err)
+	}
+
+	// Write a simple override template
+	overrideContent := `# Custom Polecat Context
+You are polecat {{ .Polecat }} with custom instructions.
+Rig: {{ .RigName }}
+`
+	if err := os.WriteFile(overrideDir+"/polecat.md.tmpl", []byte(overrideContent), 0644); err != nil {
+		t.Fatalf("failed to write override template: %v", err)
+	}
+
+	// Create Templates with the override
+	tmpl, err := NewWithOverrides("", tempDir)
+	if err != nil {
+		t.Fatalf("NewWithOverrides() error = %v", err)
+	}
+
+	// Should have one override
+	if tmpl.RoleOverrideCount() != 1 {
+		t.Errorf("RoleOverrideCount() = %d, want 1", tmpl.RoleOverrideCount())
+	}
+
+	// Should report polecat as having override
+	if !tmpl.HasRoleOverride("polecat") {
+		t.Error("HasRoleOverride('polecat') = false, want true")
+	}
+	if tmpl.HasRoleOverride("mayor") {
+		t.Error("HasRoleOverride('mayor') = true, want false")
+	}
+
+	// Render should use override
+	data := RoleData{
+		Role:    "polecat",
+		RigName: "myrig",
+		Polecat: "TestCat",
+	}
+	output, err := tmpl.RenderRole("polecat", data)
+	if err != nil {
+		t.Fatalf("RenderRole() error = %v", err)
+	}
+
+	// Should contain custom content, not embedded
+	if !strings.Contains(output, "Custom Polecat Context") {
+		t.Error("override template not used - missing 'Custom Polecat Context'")
+	}
+	if strings.Contains(output, "Idle Polecat Heresy") {
+		t.Error("embedded template used instead of override")
+	}
+	if !strings.Contains(output, "TestCat") {
+		t.Error("template variable not expanded")
+	}
+}
+
+func TestNewWithOverrides_RigOverridesTown(t *testing.T) {
+	// Create temp dirs for both town and rig overrides
+	townDir := t.TempDir()
+	rigDir := t.TempDir()
+
+	townOverrideDir := townDir + "/templates/roles"
+	rigOverrideDir := rigDir + "/templates/roles"
+
+	if err := os.MkdirAll(townOverrideDir, 0755); err != nil {
+		t.Fatalf("failed to create town override dir: %v", err)
+	}
+	if err := os.MkdirAll(rigOverrideDir, 0755); err != nil {
+		t.Fatalf("failed to create rig override dir: %v", err)
+	}
+
+	// Write town override
+	townContent := "# Town Polecat\nTown override: {{ .Polecat }}"
+	if err := os.WriteFile(townOverrideDir+"/polecat.md.tmpl", []byte(townContent), 0644); err != nil {
+		t.Fatalf("failed to write town override: %v", err)
+	}
+
+	// Write rig override (should win)
+	rigContent := "# Rig Polecat\nRig override: {{ .Polecat }}"
+	if err := os.WriteFile(rigOverrideDir+"/polecat.md.tmpl", []byte(rigContent), 0644); err != nil {
+		t.Fatalf("failed to write rig override: %v", err)
+	}
+
+	// Create Templates with both overrides
+	tmpl, err := NewWithOverrides(townDir, rigDir)
+	if err != nil {
+		t.Fatalf("NewWithOverrides() error = %v", err)
+	}
+
+	// Render should use rig override (higher precedence)
+	data := RoleData{Polecat: "TestCat"}
+	output, err := tmpl.RenderRole("polecat", data)
+	if err != nil {
+		t.Fatalf("RenderRole() error = %v", err)
+	}
+
+	if !strings.Contains(output, "Rig Polecat") {
+		t.Error("rig override not used")
+	}
+	if strings.Contains(output, "Town Polecat") {
+		t.Error("town override used instead of rig override")
+	}
+}
+
+func TestNewWithOverrides_InvalidTemplate(t *testing.T) {
+	// Create a temp directory with an invalid template
+	tempDir := t.TempDir()
+	overrideDir := tempDir + "/templates/roles"
+	if err := os.MkdirAll(overrideDir, 0755); err != nil {
+		t.Fatalf("failed to create override dir: %v", err)
+	}
+
+	// Write an invalid template (unclosed action)
+	invalidContent := "# Invalid Template\n{{ .Polecat"
+	if err := os.WriteFile(overrideDir+"/polecat.md.tmpl", []byte(invalidContent), 0644); err != nil {
+		t.Fatalf("failed to write invalid template: %v", err)
+	}
+
+	// Should return error for invalid template
+	_, err := NewWithOverrides("", tempDir)
+	if err == nil {
+		t.Error("NewWithOverrides() should fail with invalid template")
+	}
+	if !strings.Contains(err.Error(), "parsing override template") {
+		t.Errorf("error should mention parsing override template: %v", err)
+	}
+}