fix(a11y): enlarge interactive targets to 24×24 (A9)

[BrianGenisio]

Summary

Closes #53 ([a11y][A9]). Composer attach/send controls and the session delete button were below the WCAG 2.2 AA 24×24 CSS pixel minimum (18×18 and 22×22). Hit areas are grown via min-width / min-height (and explicit 24×24 on delete); icon glyphs stay smaller.

Changes

In public/app.css:

• .composer__icon-btn and .composer__send-btn get min-width / min-height: 24px (toolbar SVGs remain height: 18px)
• .session-item__delete moves from 22×22 to 24×24, with flex centering so the 12×12 trash icon stays centered

Sidebar resizer widening left as optional polish (keyboard alternative already exists). No DS / A6 / D7 changes.

Test plan

• npm test (CSS hit-area guards in tests/dom/target-size-a9.test.js)
• axe shrink-only gate — passed; no baseline change
• Playwright bounding boxes in light + dark: attach image/file, Send/Stop, delete conversation all measure 24×24
• Spot-check layout at common viewport widths (composer toolbar still looks balanced; delete icon still aligns in session rows)

Made with Cursor

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 1db69615-9c41-4b0c-bb60-2a20401dd35a

📥 Commits

Reviewing files that changed from the base of the PR and between 0545b69 and 52f2435.

📒 Files selected for processing (1)

• tests/dom/target-size-a9.test.js

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📝 Walkthrough

Walkthrough

The CSS increases session delete, composer attachment, and composer send controls to minimum 24×24 pixel interaction targets. The session delete icon is centered with inline flexbox. Vitest tests parse public/app.css, calculate effective dimensions, verify target sizes, and confirm that composer toolbar glyphs remain 18px high.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the accessibility fix and the primary change to enlarge interactive targets to 24×24.
Description check	✅ Passed	The description directly explains the target-size fixes, affected controls, validation results, and intentionally excluded resizer change.
Linked Issues check	✅ Passed	The changes satisfy issue #53 by enlarging composer and delete targets, preserving glyph sizes, and adding CSS guards and validation.
Out of Scope Changes check	✅ Passed	The changes are limited to the issue scope: target-size CSS updates and tests for the affected controls.

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@tests/dom/target-size-a9.test.js`:
- Around line 25-32: Update the regular expression in pxValue to require a CSS
declaration boundary before the requested property name, preventing width or
height from matching inside min-width or min-height. Preserve the existing value
parsing and null behavior.

🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 5bbfc67c-8b38-4fca-a46a-ef5e26a9f514

📥 Commits

Reviewing files that changed from the base of the PR and between 38a76f1 and 0545b69.

📒 Files selected for processing (2)

• public/app.css
• tests/dom/target-size-a9.test.js