Release v2.2.0

✨ Features

• feat(runtime): make watch footer a status bar with refresh meta (17cdd99)
• feat(runtime): add key-binding footer to watch mode (0d9d3a1)
• feat(runtime): add persistent watch mode (splashboard watch) (7df31cb)

🐛 Bug Fixes

• fix(watch): always run teardown + tighten WatchTerminal::enter (10520c7)
• fix(runtime): draw watch dashboard at natural height, not stretched (8dd8091)

📝 Other Changes

• chore: bump version to v2.2.0 (d25c484)
• docs: cover splashboard watch in guides + README (44527b3)
• perf(watch): cut per-frame clones via generation-tracked cache reads (5ccd828)
• perf(watch): swap disk cache for in-memory backend during watch mode (5df3ae1)
• chore: update flake.nix hashes for v2.1.0 (612d765)