Both Tauri commands took a raw path string straight from the frontend
and wrote to it with no validation — any code able to call invoke()
(a compromised or malicious extension script, which run with full page
privileges) could write to any path the OS user has access to, not just
one chosen through the save dialog. Move the save-file dialog into the
Rust command itself so the only path ever used is one the native dialog
returned; the frontend now only sends the content to save.
Both were self-contained enough to live in their own modules —
src/ui/search.ts (Ctrl+F overlay, text and result-value queries) and
src/ui/export.ts (render the sheet + results to a PNG, clipboard or
file). Trims main.ts by about 150 lines.
Also fixes a real bug while it's in there: the PNG export's clipboard
fallback did btoa(String.fromCharCode(...bytes)), which blows the
call stack on large sheets (spreading a big array as call arguments).
Chunks the conversion in 0x8000-byte pieces instead.
