fix(cli): reject invalid --check and --no-check values
Previously, passing an unrecognized value to --check or --no-check (e.g.
`deno run --check=foo script.ts`) was silently ignored: the value fell
through to a debug-log branch and type-checking was left at its default,
so users got no feedback that their flag had no effect.
Restrict both flags with a clap value_parser to their only valid values
(`all` for --check, `remote` for --no-check), matching what the help text
already documents. Invalid values now produce a clear error listing the
possible values, and the accepted values continue to work. Help output
gains a consistent `[possible values: ...]` hint like other flags.
