feat(launcher): add --version / -v flag to print app version

- Exits early with `SubMiner <version>` output, no app binary required
- Maps `-v` at root level without conflicting with `stats cleanup -v`
- Adds `version: boolean` to `Args` type and default args
- Documents flag in docs-site and adds changelog fragment

launcher/types.ts

@@ -134,6 +134,7 @@ export interface Args {
   dictionaryTarget?: string;
   doctor: boolean;
   doctorRefreshKnownWords: boolean;
+  version: boolean;
   update?: boolean;
   configPath: boolean;
   configShow: boolean;