feat(help): fuzzy "Did you mean?" suggestions for command typos

Add fuzzy matching to resolveCommandPath() so that top-level command
typos (e.g. `sentry isseu`) and subcommand typos via help (e.g.
`sentry help issue lis`) now show "Did you mean: issue?" suggestions
instead of a bare "Command not found" error.

This closes the gap where `defaultCommand: "help"` in app.ts routes
unrecognized words to the help command, bypassing Stricli's built-in
Damerau-Levenshtein fuzzy matching.

- Add UnresolvedPath type to introspect.ts with fuzzy suggestions
- Use fuzzyMatch() at both top-level and subcommand resolution levels
- Update HelpJsonResult to include optional `suggestions` array
- Surface suggestions in human output ("Did you mean: X?") and JSON
- Add formatSuggestionList() with Oxford-comma grammar

Author: BYK