A11y: iframes missing title attributes (WCAG 2.4.1) #13008

Problem

10 WCAG 2.4.1 errors across 9 pages: iframes missing `title` attributes. Screen readers use `title` to identify a frame before a user enters it.

Affected iframes:

• Book preview (`#bookPreview iframe`)
• reCAPTCHA (`#register ... iframe`)

Pages affected

• Homepage
• Book page
• Search results
• Author page
• Want to Read
• Login
• Signup
• Editions page
• Book record page

Fix

Add `title` to each `<iframe` in templates:

```html

<iframe src="..." title="Book preview"></iframe> <iframe src="..." title="reCAPTCHA security challenge"></iframe> \`\`\`

Acceptance criteria

• 0 `frame-title` violations in pa11y scan across `scripts/a11y/pages.json`
• PR includes Playwright test (depends on A11y Phase 2: Playwright + axe-core integration for page-level WCAG testing #13007): `checkA11y(page, null, { runOnly: { type: 'rule', values: ['frame-title'] } })`

Baseline

10 errors, 9 pages (2026-06-23). Good first issue — mechanical, low risk, good for a new contributor.

Closes when pa11y reports 0 frame-title violations across all scanned pages.