[m1ngsama]

Four rough edges found while testing Prompt in a real pseudoterminal. This branch builds on #92; the base is feat/ascii-art-tui and should move to main once #92 merges.

Closes #93, closes #94, closes #95, closes #96.

• Home says how many events are not shown ("还有 3 项"). When a single wrapped event does not fit the remaining rows, it stays reachable by scrolling instead of disappearing, as it did at 24×10.
• Without a timetable, Home shows the next event and its countdown when the first event still fits below it.
• In the one-year heatmap, ↑↓ moves one day, ←→ one week, and the selected day's date, event count, and events appear below the grid. ⏎ opens that day as a list. When the Events tab already draws the heatmap, the browse menu offers "逐日查看活跃度".
• ASCII terminals show an ASCII emblem with the same ring, eyes, and arc as the Braille badge. The emblem is 26 columns by 11 rows; when it and the tagline do not fit, the three-line wordmark is used as before.

Validation: npm run check (1,084 tests, package check, audit with zero vulnerabilities). Checked in a real pseudoterminal at 24×10, 30×12, and 80×24, and with LANG=C. No new dependencies.