Fix mail read auto-ack and add Mayor startup directive

- Remove auto-ack on mail read so handoff messages persist
- Add STARTUP PROTOCOL directive for Mayor and Polecat roles
- Agents now get explicit instructions to check in on startup

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

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

internal/cmd/mail.go

@@ -373,8 +373,9 @@ func runMailRead(cmd *cobra.Command, args []string) error {
 		return fmt.Errorf("getting message: %w", err)
 	}
 
-	// Mark as read
-	_ = mailbox.MarkRead(msgID)
+	// Note: We intentionally do NOT mark as read/ack on read.
+	// User must explicitly delete/ack the message.
+	// This preserves handoff messages for reference.
 
 	// JSON output
 	if mailReadJSON {

internal/cmd/prime.go

@@ -88,6 +88,9 @@ func runPrime(cmd *cobra.Command, args []string) error {
 	// Run gt mail check --inject to inject any pending mail
 	runMailCheckInject(cwd)
 
+	// Output startup directive for roles that should announce themselves
+	outputStartupDirective(ctx)
+
 	return nil
 }
 
@@ -385,6 +388,30 @@ func runBdPrime(workDir string) {
 	}
 }
 
+// outputStartupDirective outputs role-specific instructions for the agent.
+// This tells agents like Mayor to announce themselves on startup.
+func outputStartupDirective(ctx RoleContext) {
+	switch ctx.Role {
+	case RoleMayor:
+		fmt.Println()
+		fmt.Println("---")
+		fmt.Println()
+		fmt.Println("**STARTUP PROTOCOL**: You are the Mayor. Please:")
+		fmt.Println("1. Announce: \"Mayor, checking in.\"")
+		fmt.Println("2. Check mail: `gt mail inbox`")
+		fmt.Println("3. If there's a 🤝 HANDOFF message, read it and summarize")
+		fmt.Println("4. If no mail, await user instruction")
+	case RolePolecat:
+		fmt.Println()
+		fmt.Println("---")
+		fmt.Println()
+		fmt.Println("**STARTUP PROTOCOL**: You are a polecat. Please:")
+		fmt.Println("1. Check mail: `gt mail inbox`")
+		fmt.Println("2. If assigned work, begin immediately")
+		fmt.Println("3. If no work, announce ready and await assignment")
+	}
+}
+
 // runMailCheckInject runs `gt mail check --inject` and outputs the result.
 // This injects any pending mail into the agent's context.
 func runMailCheckInject(workDir string) {