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/stream-monaco/eslint.config.js

@@ -0,0 +1,19 @@
+import antfu from '@antfu/eslint-config'
+
+export default antfu(
+  {
+    ignores: [
+      // eslint ignore globs here
+      'examples/streaming-demo/src/shims-vue.d.ts',
+      'src/worker/*.js',
+      './test/',
+      './scripts/',
+      'docs/',
+    ],
+  },
+  {
+    rules: {
+      // overrides
+    },
+  },
+)