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/packages/markdown-parser/test/multiple-links-same-line.test.ts

@@ -0,0 +1,26 @@
+import { describe, expect, it } from 'vitest'
+import { getMarkdown, parseMarkdownToStructure } from '../src'
+
+function flatten(nodes: any[]): any[] {
+  const out: any[] = []
+  for (const n of nodes ?? []) {
+    out.push(n)
+    if (Array.isArray(n?.children))
+      out.push(...flatten(n.children))
+  }
+  return out
+}
+
+describe('parseMarkdownToStructure - multiple links same line', () => {
+  it('parses 3 adjacent links as 3 link nodes', () => {
+    const md = getMarkdown()
+    const markdown = '[citation](http://url1)  [citation](http://url1) [citation](http://url1)'
+    const nodes = parseMarkdownToStructure(markdown, md)
+
+    const all = flatten(nodes)
+    const links = all.filter(n => n?.type === 'link')
+
+    expect(links).toHaveLength(3)
+    expect(links.map(l => l.href)).toEqual(['http://url1', 'http://url1', 'http://url1'])
+  })
+})