Fix hook message duplication in TUI

Two bugs:
1. createCustomMessage was returning role: 'user' instead of preserving
   the hook message structure (role: 'hookMessage', customType, etc.)
2. rebuildChatFromMessages wasn't clearing the container before rebuilding

packages/coding-agent/src/core/session-manager.ts

@@ -165,10 +165,13 @@ export function createSummaryMessage(summary: string, timestamp: string): AgentM
 /** Convert CustomMessageEntry to AgentMessage format */
 function createCustomMessage(entry: CustomMessageEntry): AgentMessage {
 	return {
-		role: "user",
+		role: "hookMessage",
+		customType: entry.customType,
 		content: entry.content,
+		display: entry.display,
+		details: entry.details,
 		timestamp: new Date(entry.timestamp).getTime(),
-	};
+	} as AgentMessage;
 }
 
 /** Generate a unique short ID (8 hex chars, collision-checked) */

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -1208,6 +1208,7 @@ export class InteractiveMode {
 	}
 
 	private rebuildChatFromMessages(): void {
+		this.chatContainer.clear();
 		const context = this.sessionManager.buildSessionContext();
 		this.renderSessionContext(context);
 	}