fix(e2e): poll for kernel status after trust approval and wait for button enabled

[rgbkrk]

Fixes the Trust Dialog E2E runner. Two bugs found by running the test locally and watching the app:

1. Approve button disabled during loading race

The daemon:ready event triggers checkTrust() which briefly sets loading=true, disabling the dialog buttons. If WebDriver tries to click during that window, waitForClickable times out after 5s. Fix: added waitForEnabled({ timeout: 10000 }) before waitForClickable.

2. Kernel status read too early after approval

handleTrustApprove calls launchKernel("auto", "auto") as fire-and-forget (no await). The kernel status propagates via RuntimeStateDoc sync, so it's still not_started when read immediately. Fix: replaced the single-read expect with a 10s waitUntil poll for starting/idle/busy.

Local test result after fix:

Trust dialog appeared
Kernel status before trust approval: not_started
Clicked approve button  
Dialog dismissed in 307ms
Kernel status after dialog closed: idle
✓ should close trust dialog on single click without waiting for kernel (1.5s)

PR submitted by @rgbkrk's agent Quill, via Zed

[rgbkrk]

CI Results

5/8 E2E runners pass:

Runner	Status
Smoke	✅
UI (Cell Visibility)	✅
UV Prewarmed	✅
Deno	✅
UV Pyproject	✅
Trust Dialog	❌ trust dialog never appears
UV Inline Deps	❌ trust dialog never appears
Conda Inline Deps	❌ trust dialog never appears

Root cause of 3 failures: The trust dialog doesn't appear on CI even though the fixture notebook (2-uv-inline.ipynb) has inline deps and no trust_signature. The daemon's trust verification may not be reading runt.uv.dependencies from the notebook metadata correctly, or the trust check on Linux resolves differently.

This is a daemon-side trust detection issue, not a test issue. The trust dialog fix in this PR (polling for kernel status, waiting for button enabled) is correct — it just can't be exercised because the dialog never shows.

Recommend: merge this PR for the trust dialog fix, investigate the trust detection separately.