feat(i18n): set up glossary (#2198)

This pull request introduces the initial glossary for the project to
improve the translation quality.

Implements #2148.

### TODOs

- [x] Add the definition YAML
- [x] Add a generator to produce Crowdin-compatible (TBX v3) format
- [x] AGENTS.md
- [ ] ~Workflow~ (Split to another PR)
- [ ] ~Skills~ (Same as above)

vitest.config.ts

@@ -9,6 +9,7 @@ export default defineConfig({
       'packages/cap-vite',
       'packages/ccc',
       'packages/core-agent',
+      'packages/i18n',
       'packages/better-ws',
       'packages/plugin-sdk',
       'packages/plugin-sdk-tamagotchi',