refactor: extract waitForAgentToFinish helper to pages/sessions

[empiricalrun]

Summary

Adds a waitForAgentToFinish(page) helper to tests/pages/sessions.ts and replaces 4 scattered inline usages in tests/sessions.spec.ts.

What changed

tests/pages/sessions.ts

Added a new exported helper:

export async function waitForAgentToFinish(page: Page, timeout = 60000): Promise<void> {
  await expect(page.getByRole('button', { name: /^Stop/ })).toBeHidden({ timeout });
}

tests/sessions.spec.ts

Replaced 4 occurrences of the "wait for agent" pattern that had slight inconsistencies:

Before	Location
await expect(page.getByRole('button', { name: /^Stop/ })).toBeHidden({ timeout: 60000 })	Close session test
const stopButton = …('Stop'); if (await stopButton.isVisible()) { await expect(stopButton).toBeHidden(…) }	Edit message test (conditional + different selector)
await expect(stopButton).toBeHidden({ timeout: 60000 })	Session creation test (×2)

All replaced with:

await waitForAgentToFinish(page);

Why this change

• Standardizes the stop-button check — previously used /^Stop/ regex in some places and the exact string 'Stop' in others (the regex handles keyboard-shortcut variants like "Stop ⌃C")
• Removes a redundant conditional in the edit-message test — expect().toBeHidden() already passes immediately when the element is already hidden, so the if (isVisible()) guard was unnecessary
• Makes intent clear — waitForAgentToFinish(page) reads naturally in the test flow
• Reusable — future tests can import this from pages/sessions instead of reimplementing it

PR created from session #121603

^{Updated at 2026-04-19 05:02:27.183 UTC}