fix: record user messages for MCP-triggered agent prompts

Ensures MCP-originated prompts emit timeline events in real-time by calling recordUserMessage before starting agent runs. Fixes issue where messages sent via MCP tools only appeared after page refresh.

- Add recordUserMessage call in send_agent_prompt tool
- Add recordUserMessage call in create_coding_agent with initialPrompt
- Both paths now mirror UI-sent message behavior

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

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

packages/server/src/server/agent/mcp-server.ts

@@ -195,6 +195,14 @@ export async function createAgentMcpServer(
       });
 
       if (initialPrompt) {
+        try {
+          agentManager.recordUserMessage(snapshot.id, initialPrompt);
+        } catch (error) {
+          console.error(
+            `[Agent MCP] Failed to record initial prompt for ${snapshot.id}:`,
+            error
+          );
+        }
         try {
           startAgentRun(agentManager, snapshot.id, initialPrompt);
         } catch (error) {
@@ -326,6 +334,15 @@ export async function createAgentMcpServer(
         await agentManager.setAgentMode(agentId, sessionMode);
       }
 
+      try {
+        agentManager.recordUserMessage(agentId, prompt);
+      } catch (error) {
+        console.error(
+          `[Agent MCP] Failed to record user message for ${agentId}:`,
+          error
+        );
+      }
+
       startAgentRun(agentManager, agentId, prompt);
       const snapshot = agentManager.getAgent(agentId);