fix(pi): reopen persisted conversation sessions

electron/coding-runtime/pi/runtime.ts

@@ -191,6 +191,7 @@ export function createPiManagedWorkerOpener(
   return async (input) => {
     const resourcesStartedAt = now();
     const registered = await options.registry.prepare(input.conversation);
+    const existingSession = input.existingSession ?? registered.session ?? undefined;
     const model = registered.conversation.model;
     if (!model || registered.conversation.modelResolution !== 'resolved') {
       throw new CodingRuntimeContractError(
@@ -238,11 +239,12 @@ export function createPiManagedWorkerOpener(
       'resources.ready',
       now() - resourcesStartedAt,
       now(),
+      !existingSession,
     );
     const sessionKey = validateSessionKey(
-      input.existingSession?.sessionKey ?? createSessionKey(),
+      existingSession?.sessionKey ?? createSessionKey(),
     );
-    if (input.existingSession && input.fork) {
+    if (existingSession && input.fork) {
       throw new Error('Pi worker cannot reopen and fork a session at the same time');
     }
     const process = createProcess({
@@ -272,6 +274,7 @@ export function createPiManagedWorkerOpener(
         'worker.spawn',
         now() - spawnStartedAt,
         now(),
+        !existingSession,
       );
       if (input.fork?.sourceEntryId) {
         await process.request({ type: 'fork', entryId: input.fork.sourceEntryId });
@@ -287,10 +290,11 @@ export function createPiManagedWorkerOpener(
         'rpc.ready',
         now() - readyStartedAt,
         now(),
+        !existingSession,
       );
       const piSessionId = response.data?.sessionId?.trim();
       if (!piSessionId) throw new Error('Pi worker did not return a session id');
-      if (input.existingSession && input.existingSession.piSessionId !== piSessionId) {
+      if (existingSession && existingSession.piSessionId !== piSessionId) {
         throw new CodingRuntimeContractError(
           'CODING_SESSION_UNREADABLE',
           'Pi reopened a different Conversation session',
@@ -327,6 +331,7 @@ export function createPiManagedWorkerOpener(
         'session.open',
         now() - sessionStartedAt,
         now(),
+        !existingSession,
       );
       return {
         worker: new ManagedPiConversationWorker(
@@ -356,12 +361,13 @@ function recordManagedMilestone(
   milestone: Extract<PiRuntimeMilestone, 'resources.ready' | 'worker.spawn' | 'rpc.ready' | 'session.open'>,
   durationMs: number,
   at: number,
+  cold: boolean,
 ): void {
   listener?.(createPiRuntimeTelemetryEvent({
     milestone,
     conversationId: input.conversation.conversationId,
     workerGeneration: input.generation,
-    cold: !input.existingSession,
+    cold,
     durationMs,
     at,
   }));