ci: nightly browser suite; fix stale session-id extraction in browser tests

WIP: the suite still has failures on a clean master that are not fixed here.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

test/opencode-resize.test.ts

@@ -123,7 +123,8 @@ describe('OpenCode session initial resize', () => {
         body: JSON.stringify({ workingDir: '/tmp', name: 'oc-resize-test' }),
       });
       const data = await res.json();
-      return data.id ?? data.session?.id;
+      // POST /api/sessions answers in the { success, data: { session } } envelope.
+      return data.data?.session?.id ?? data.id ?? data.session?.id;
     });
 
     expect(sessionId).toBeTruthy();
@@ -168,7 +169,8 @@ describe('OpenCode session initial resize', () => {
         body: JSON.stringify({ workingDir: '/tmp', name: 'oc-earlyret-test' }),
       });
       const data = await res.json();
-      return data.id ?? data.session?.id;
+      // POST /api/sessions answers in the { success, data: { session } } envelope.
+      return data.data?.session?.id ?? data.id ?? data.session?.id;
     });
 
     expect(sessionId).toBeTruthy();
@@ -219,7 +221,8 @@ describe('OpenCode session initial resize', () => {
         body: JSON.stringify({ workingDir: '/tmp', name: 'oc-refresh-test' }),
       });
       const data = await res.json();
-      return data.id ?? data.session?.id;
+      // POST /api/sessions answers in the { success, data: { session } } envelope.
+      return data.data?.session?.id ?? data.id ?? data.session?.id;
     });
 
     expect(sessionId).toBeTruthy();
@@ -287,7 +290,8 @@ describe('OpenCode close modal text', () => {
         body: JSON.stringify({ workingDir: '/tmp', name: 'oc-close-test', mode: 'opencode' }),
       });
       const data = await res.json();
-      return data.id ?? data.session?.id;
+      // POST /api/sessions answers in the { success, data: { session } } envelope.
+      return data.data?.session?.id ?? data.id ?? data.session?.id;
     });
 
     expect(sessionId).toBeTruthy();
@@ -329,7 +333,8 @@ describe('OpenCode close modal text', () => {
         body: JSON.stringify({ workingDir: '/tmp', name: 'cc-close-test' }),
       });
       const data = await res.json();
-      return data.id ?? data.session?.id;
+      // POST /api/sessions answers in the { success, data: { session } } envelope.
+      return data.data?.session?.id ?? data.id ?? data.session?.id;
     });
 
     expect(sessionId).toBeTruthy();

test/perf-browser.test.ts

@@ -69,7 +69,8 @@ async function createSession(page: Page, name: string): Promise<string> {
       body: JSON.stringify({ workingDir: '/tmp', name: n }),
     });
     const data = await res.json();
-    return data.id ?? data.session?.id;
+    // POST /api/sessions answers in the { success, data: { session } } envelope.
+    return data.data?.session?.id ?? data.id ?? data.session?.id;
   }, name);
   return result as string;
 }