test(config): the session render rig waits for the reads it asserts (#22269)

The session route issues worktree.show, session.tabs.list and terminal.list from
effects that run after the commit painting 'Terminal', so reading
__orcaRenderCheckRequests where openRoute resolves is a snapshot taken before the
burst. Under a 20x CPU throttle none of the three is in it, which is the shape
the loaded CI job hit twice. waitForRecordedRequests polls the double's own log
under a 30s bound and names what never arrived.

Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb

config/scripts/mobile-web-app-render-harness.mjs

@@ -439,6 +439,38 @@ export function installShellDouble({
   globalThis.orcaBridge = channel
 }
 
+/** How long a check waits for a mount's reads before it reports what the page did send. */
+const RECORDED_REQUEST_MS = 30_000
+
+/**
+ * The double's request log, once every method named is in it.
+ *
+ * A route issues its first reads from effects that run after the commit painting its chrome, so a
+ * snapshot taken where the awaited text lands is a race a loaded machine loses. The bound names
+ * what never arrived and what did.
+ */
+export async function waitForRecordedRequests(
+  page,
+  methods,
+  { boundMs = RECORDED_REQUEST_MS } = {}
+) {
+  const started = Date.now()
+  for (;;) {
+    const requests = await page.evaluate(() => globalThis.__orcaRenderCheckRequests ?? [])
+    const missing = methods.filter((method) => !requests.some((one) => one.method === method))
+    if (missing.length === 0) {
+      return requests
+    }
+    if (Date.now() - started > boundMs) {
+      throw new Error(
+        `[render-harness] the page never asked for ${missing.join(', ')} in ${String(boundMs)}ms; ` +
+          `it asked for ${JSON.stringify(requests.map((one) => one.method))}`
+      )
+    }
+    await page.waitForTimeout(25)
+  }
+}
+
 /**
  * The page server the render checks run against: the built bundle, under the shell's own policy.
  *

config/scripts/mobile-web-app-session-render.test.mjs

@@ -11,7 +11,8 @@ import {
   installShellDouble,
   readBridgeFaultGrant,
   readBridgeProtocolVersion,
-  readShellCsp
+  readShellCsp,
+  waitForRecordedRequests
 } from './mobile-web-app-render-harness.mjs'
 
 /**
@@ -212,6 +213,9 @@ async function openRoute(route, awaitText, replies = {}, options = {}) {
 /** The session header renders it, so the chrome is on screen before this reads the tree. */
 const BACK_LABEL = 'Back to worktrees'
 
+/** The header's live title, the tab snapshot and the terminal inventory. */
+const SESSION_MOUNT_READS = ['worktree.show', 'session.tabs.list', 'terminal.list']
+
 describeRender(
   'the session route in a real browser',
   () => {
@@ -341,14 +345,12 @@ describeRender(
       // The precondition every assertion above needs: a screen that mounted and asked for nothing
       // would paint the same chrome. The three reads are the header's live title, the tab snapshot
       // and the terminal inventory, each carrying the workspace the route named.
+      //
+      // Waited for and not read at the paint: all three are issued from effects that run after the
+      // commit putting 'Terminal' on screen, which is why this case reds on CI's loaded job and
+      // never here. Under a 20x CPU throttle the snapshot at the paint holds none of them.
       const opened = await openRoute(SESSION_ROUTE, 'Terminal')
-      const requests = await opened.page.evaluate(() => globalThis.__orcaRenderCheckRequests ?? [])
-      for (const method of ['worktree.show', 'session.tabs.list', 'terminal.list']) {
-        expect(
-          requests.some((request) => request.method === method),
-          method
-        ).toBe(true)
-      }
+      const requests = await waitForRecordedRequests(opened.page, SESSION_MOUNT_READS)
       expect(JSON.stringify(requests)).toContain(WORKTREE)
       await opened.page.close()
     }, 120_000)