Extend automated browser coverage beyond Chromium

Problem

docs/SYSTEM_STATE.md states that automated browser coverage currently uses Chromium, while Firefox, Safari, and real-device visual review remain manual.

Goal

Increase confidence in the recruiter/visitor paths without creating an expensive browser matrix.

Scope

• Add Firefox to the automated Playwright critical-path suite.
• Identify the smallest Safari/WebKit coverage that is reliable in CI.
• Define a documented manual real-device checklist for behavior that cannot be trusted through emulation alone.
• Prioritize navigation, appearance modes, resume/contact flows, and Ask Mantosh interaction over exhaustive visual snapshots.

Acceptance criteria

• Critical visitor journeys run automatically in Chromium and Firefox.
• WebKit/Safari coverage is either automated for the supported subset or explicitly documented with rationale.
• A concise real-device manual checklist exists for release-sensitive changes.
• Browser-specific failures are actionable and not hidden by broad retries.
• Release-confidence documentation reflects the new matrix.

Start by reading docs/SYSTEM_STATE.md and locating the automated Playwright critical-path suite. Extend the visitor journeys for Chromium and Firefox, investigate the smallest reliable WebKit/Safari subset, and define the manual real-device checklist. Done means the acceptance criteria are met, browser failures remain actionable, and release-confidence documentation reflects the matrix.