Description

Like -p (preview), add -e / --export [file] to export a named markdown file straight to printable house-style HTML from the command line — headless, no TUI. Mirrors Ctrl+E: render via export.Write, open in browser, print the output path, exit. Requires a file arg.

Acceptance Criteria

• #1 glint -e (and --export / -export / --e) exports the file to house-style HTML and opens it in the browser
• #2 Prints the output path; headless (no editor TUI); errors if no file given
• #3 README + help document the flag

Implementation Notes

main.go -e/--export standalone command → App.ExportFile(path): writeExport (read+export.Write, no browser) then OpenInBrowser best-effort; prints output path; errors if no file. Extracted shared exportOptions (Ctrl+E reuses it). README usage + help document -e. 2 app tests green.