sm 0.5.0

Changelog

• 6c2be79 Merge feat/tui-settings-dialog: in-TUI settings dialog (',' key)
• 8932950 feat(config): add Save (canonical full rewrite) and ValidHex
• 27ca2d6 feat(ui): advertise settings in the help bar; document ',' in README
• e3d6b56 feat(ui): settings dialog skeleton — open with ',', navigate, render, close
• 21f6a47 feat(ui): settings enum cycling and bool toggling
• ba95fe4 feat(ui): settings inline text/hex editing with validation
• 065b1e0 feat(ui): settings save — write config.json, confirm, inline retry on failure
• 1a6f8d8 feat(ui): thread config path and startup config into the Model
• 2423d89 fix(ui): dialogInfo mouse dismissal + settings test hardening
• 3d2dc10 test(ui): hot-apply invariant test discriminates openIn and styles too