Calendar / agenda view for interviews

[Joun-Mikhail]

Summary

Add a calendar (month) and agenda (list) view for interviews, alongside the existing Upcoming/Past/All filters on /interviews.

Motivation

The interviews list is chronological but it is hard to see week-at-a-glance density or spot scheduling clashes.

Proposed approach

• New view toggle on InterviewsPage (List | Calendar).
• Render a lightweight month grid from useAllInterviews data — no heavy calendar dep; reuse the existing date helpers in src/lib/format.ts.
• Clicking a day scrolls/links to that day’s interviews.

Acceptance criteria

• Month grid shows interview counts per day.
• Clicking an interview opens its application detail.
• Keyboard navigable; works in light/dark themes.