fix: persist first Pi user message in JSONL

src/agents/pi-embedded-runner.ts

@@ -1474,11 +1474,6 @@ export async function runEmbeddedPiAgent(params: {
             : sandbox.workspaceDir
           : resolvedWorkspace;
         await fs.mkdir(effectiveWorkspace, { recursive: true });
-        await ensureSessionHeader({
-          sessionFile: params.sessionFile,
-          sessionId: params.sessionId,
-          cwd: effectiveWorkspace,
-        });
 
         let restoreSkillEnv: (() => void) | undefined;
         process.chdir(effectiveWorkspace);