feat(desktop): embed BoosAPI Desktop client as a subproject

Vendor the rebranded BoosAPI Desktop client (Tauri + Vue) into metapi as
a monorepo subdirectory under desktop/. Source only — node_modules,
dist, Cargo target and the upstream .git history are excluded.

desktop/ keeps its own independent Cargo workspace (desktop/src-tauri
with crates/*); it is not part of the backend boosapi crate, so a
`cargo check` at the metapi root still compiles only the backend. Build
the desktop app from desktop/src-tauri per desktop/README.md.

Note: app icons are still placeholder assets pending the final BoosAPI
logo. The updater signing keys live outside the repo and are not
included.

desktop/libs/markstream-vue/test/html-block-regressions.test.ts

@@ -0,0 +1,33 @@
+import { getMarkdown, parseMarkdownToStructure } from 'stream-markdown-parser'
+import { describe, expect, it } from 'vitest'
+import { collect, textIncludes } from './utils/midstate-utils'
+
+describe('html block regressions', () => {
+  const md = getMarkdown('html-block-regressions')
+
+  it('keeps fenced code inside html block content', () => {
+    const markdown = `<div>
+\`\`\`js
+console.log(1)
+\`\`\`
+</div>`
+
+    const nodes = parseMarkdownToStructure(markdown, md)
+    expect(nodes.length).toBe(1)
+    const htmlBlock: any = nodes[0]
+    expect(htmlBlock.type).toBe('html_block')
+    expect(htmlBlock.tag).toBe('div')
+    expect(htmlBlock.loading).toBe(false)
+    expect(htmlBlock.raw).toContain('```js')
+
+    const codeBlocks = nodes.filter((n: any) => n.type === 'code_block' || n.type === 'fence')
+    expect(codeBlocks.length).toBe(0)
+  })
+
+  it('does not treat JSON arrays like "[14]" as references', () => {
+    const markdown = `<question>[{"id":"1","pages":[14],"content":"本次测试的目的是什么？"},{"id":"2","pages":[5,15],"content":"如何根据MODULEID查找对应的测试信息？"}]</question>`
+    const nodes = parseMarkdownToStructure(markdown, md) as any[]
+    expect(collect(nodes, 'reference').length).toBe(0)
+    expect(textIncludes(nodes, '[14]')).toBe(true)
+  })
+})