Compose translation scenarios and prepare Gloss 0.8.3

[SunChJ]

Summary

• model Gloss as reusable core capabilities composed into browser and PDF business scenarios
• expose stable CLI mappings for capabilities, text, browser, and batch PDF automation
• require the compatible BabelDOC runtime that fixes o200k_base and keep one PDF service warm
• add signed release discovery, recoverable in-App Homebrew upgrades, and automatic tap dispatch
• focus the App UI and lifecycle on browser/PDF while removing dormant macOS Services
• make browser capabilities distribution-aware: Homebrew exposes Chrome only and Apple-signed/profiled builds may expose Safari

Safety and delivery

• signed manifest v2 binds both App archives and exact cask bytes
• updater helper re-verifies metadata, stages a recovery App, and only exits after readiness acknowledgement
• command timeout/cancellation terminates the complete process group with bounded 16 MiB output capture
• ad-hoc release artifacts omit the Safari appex so PlugInKit cannot register an unusable extension

Validation

• swift test: 290 tests, 5 conditionally skipped, 0 failures
• swift build -c release: Gloss, gloss-cli, and gloss-update-helper
• strict Swift format lint, shell syntax, plist/YAML parsing, and diff checks
• cross-repository dummy release manifest/checksum/cask validation
• real 15-page Attention Is All You Need PDF: 31.56 seconds, 15-page 2.3 MB selectable-Chinese output on BabelDOC 0.6.4+gloss.5

Full Gloss.app packaging remains covered by the release workflow because the private browser-extension checkout is not present in this local workspace.