feat(cli): talk version as a subcommand

A bare `talk version` was spoken as an announcement because only the
--version flag existed. The subcommand prints the same line.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

README.md

@@ -28,6 +28,7 @@ dependencies.
 | `talk test` | speak a test sentence; shows provider and timings (`--lang`, `--provider`, `--voice`); `--toast` sends a test notification instead |
 | `talk doctor` | self-diagnosis: config, daemon, audio, providers, notifications, mute, laws (`--probe`, `--json`) |
 | `talk setup` | first-time setup in a few questions: language, voices with preview, quiet hours, config.toml |
+| `talk version` | version and commit (also `talk --version`) |
 
 Say flags (also for `talk "text"`): `--wait`, `--now`, `--priority`,
 `--voice`, `--lang`, `--provider`.