fix(acp): log child process stderr + global name alias (#3135, #3134)

- Forward ACP child process stderr to server logs so errors from
  claude-agent-acp (API key issues, crashes) are visible for debugging
- Move 'name' alias from create-only to redactSession() so it's
  present in all session responses (GET, list, create)

Author: OneStepAt4time

src/routes/context.ts

@@ -310,6 +310,10 @@ export function redactSession(session: Record<string, unknown>): Record<string,
   if (activeSubagents instanceof Set) {
     (redacted as Record<string, unknown>).activeSubagents = [...activeSubagents];
   }
+  // Issue #3134: Add 'name' alias for backward compat (API consumers expect 'name')
+  if (redacted.displayName !== undefined && redacted.name === undefined) {
+    (redacted as Record<string, unknown>).name = redacted.displayName;
+  }
   return redacted;
 }
 

src/routes/sessions.ts

@@ -470,9 +470,7 @@ export function registerSessionRoutes(app: FastifyInstance, ctx: RouteContext):
       ? 'Session created but prompt not delivered: ACP is disabled. Set AEGIS_ACP_ENABLED=true or add "acpEnabled": true to config to enable Claude Code sessions.'
       : undefined;
 
-    // Issue #3134: Include 'name' alias for backward compat (API consumers expect 'name')
-    const sessionResponse = redactSession(session as unknown as Record<string, unknown>);
-    return reply.status(201).send({ ...sessionResponse, name: sessionResponse.displayName ?? sessionResponse.name, promptDelivery, ...(acpWarning ? { warning: acpWarning } : {}) });
+    return reply.status(201).send({ ...redactSession(session as unknown as Record<string, unknown>), promptDelivery, ...(acpWarning ? { warning: acpWarning } : {}) });
   }
   registerWithLegacy(app, 'post', '/v1/sessions', {
     config: {

src/services/acp/backend.ts

@@ -962,6 +962,15 @@ export function createDefaultAcpBackendClient(
     ...options.childProcessOptions,
     cwd: context.cwd,
   });
+  // Issue #3135: Forward ACP child process stderr for debugging.
+  // Without this, errors from claude-agent-acp (API key issues, crashes)
+  // are silently discarded, making diagnosis impossible.
+  child.on('stderr', (event) => {
+    const text = typeof event.chunk === 'string' ? event.chunk.trim() : '';
+    if (text) {
+      console.error(`[ACP stderr:${context.durableSessionId.slice(0, 8)}] ${text}`);
+    }
+  });
   return new AcpJsonRpcClient({
     ...options.jsonRpcClientOptions,
     child,