fix: correct fish completion output

[keta1]

Description

This fixes fish completion output for m-cli. The fish completion parser currently uses string match in conditionals without quiet mode, which can leak matched option names as duplicate completion candidates.

The duplicate output can be reproduced with fish's complete -C builtin, which computes completions for a supplied command line.

Before:

$ fish -c 'complete -C "m battery "'
  --help
  --status
--help    Show this help message
--status  Show the current battery status

After:

$ fish -c 'complete -C "m battery "'
--help    Show this help message
--status  Show the current battery status

This also quotes parsed help lines and completion tokens to avoid empty/glob-like matching surprises, and completes option values before falling back to option-name completions.

Verification

• fish -n completions/fish/m.fish
• fish -c 'complete -C "m battery --"' only shows --help and --status once
• fish -c 'complete -C "m appearance --darkmode "' completes disable and enable
• fish -c 'complete -C "m appearance --iconsize m"' completes medium