[ruibaby]

Summary

• Add a ContentSnippet custom model and generated API client for reusable rich-text snippets.
• Add management pages for creating, editing, searching, and deleting snippets.
• Integrate snippets with Halo's default editor through slash commands, the toolbox, and a selection bubble action for saving selected content.
• Preserve HTML formatting when saving and inserting snippets, and provide responsive desktop and mobile layouts.
• Configure the local development server on port 8091.

Behavior

• Snippets are inserted as HTML snapshots; later snippet edits do not change content already inserted into posts.
• Saving a selection does not alter the current post.
• Custom model APIs use Halo's default authorization; no additional role templates are introduced.

Validation

• pnpm --dir ui type-check
• ./gradlew clean build --offline
• git diff --check
• Manually verified on Halo 2.26.0 with desktop and 390x844 mobile viewports:
  • snippet CRUD and search;
  • slash-command and toolbox insertion;
  • selection snapshots with multiple paragraphs, bold text, and links;
  • original post preservation and snippet reinsertion;
  • empty and whitespace validation, cancel, failure/retry, and double-click handling;
  • save modal accessibility with zero axe violations.

Known validation limitation

Targeted ESLint was attempted but remains blocked by missing UnoCSS rule definitions in the existing repository configuration: @unocss/enforce-class-compile, @unocss/order, and @unocss/order-attributify.