feat(templates): add Claude Code Templates marketplace

- Add template repository management and component discovery
- Implement template installation for agents, commands, hooks, MCPs, skills, settings
- Support multi-app installation (Claude/Codex/Gemini)
- Add frontend components for browsing and installing templates
- Include i18n translations for zh/en/ja

src/components/templates/index.ts

@@ -0,0 +1,5 @@
+export { TemplatesPage } from "./TemplatesPage";
+export { ComponentCard } from "./ComponentCard";
+export { ComponentDetail } from "./ComponentDetail";
+export { CategoryFilter } from "./CategoryFilter";
+export { RepoManager } from "./RepoManager";