Stabilize comment geometry recovery test

[MaggieAppleton]

Summary

• select a bounded phrase in the compact comment geometry recovery test
• keep the tall document while guaranteeing the widened viewport has valid marker geometry

Root cause

The test selected the entire tall paragraph. On Linux at 430px, no 44px marker position could avoid the selected prose, so the product correctly kept the marker beyond the passage and the test timed out.

Verification

• bun run ci
• bun run types
• focused Playwright test
• focused Playwright test repeated 10 times in parallel