Template kit 1.4.1

Template kit 1.4.1

Synchronises developer previews with the platform SEO/accessibility release:

• Shared enrolment access-panel spacing, wrapping and keyboard focus.
• Correct event heading hierarchy and shared map target presentation.
• Platform-owned prose contrast without duplicated opacity reduction.
• Regression coverage for preview stylesheet and embedding parity.

No template contract or manifest changes. Existing first-party templates remain
compatible with kit 1.4.0. This patch changes developer-preview styling and does
not publish tenant content or select a new template for an existing website.

Verified in PR #10: 59 tests passed, package dry run passed, and the vendored
stylesheet matches the platform source.

Platform release: Port60Labs/multi-tenant-services#322
Kit changes: #10