bug(ui): Esc while renaming a Workspace chat saves the edit instead of cancelling #3459

Summary

The typed text becomes the title.

Category: functional · Severity: Medium · Validated: source

Context

Found by the click-through UI sweep of a local instance (dev @ c90c711ee, 1.0.0-rc1), fixture agents only.

Repro

1. In the Workspace sidebar start renaming one of your chats.
2. Type a different title and press Esc.

Expected

Esc abandons the edit; the title is unchanged.

Observed

The typed text becomes the title.

Validation

src/frontend/src/components/portal/PortalEditableTitle.vue:114-126 — cancel() only flips editing; unmounting the input fires @blur, and onBlur() commits whenever the draft differs from the saved value.

Acceptance Criteria

• The repro above gives the Expected result at 1440 and 768, in light and dark.
• A regression test pins the behaviour (unit or Playwright, whichever tier can observe it).
• No new raw-palette classes or hand-rolled primitives are introduced by the fix (docs/memory/design-system-contract.md).

Technical Notes

Evidence screenshots (kept on the machine that ran the sweep; the evidence folder is gitignored because the repository is public):

• docs/testing/ui-sweep/evidence/2026-10-09-all/c668b9a8-1.png

Found by /ui-sweep --all @ c90c711