feat(vscodex): add remote Codex collaboration module

.github/workflows/release.yml

@@ -77,7 +77,15 @@ jobs:
         with:
           node-version: 22
           cache: npm
-          cache-dependency-path: frontend/package-lock.json
+          cache-dependency-path: |
+            frontend/package-lock.json
+            aether-vscodex/web/package-lock.json
+
+      - name: Build aether-vscodex web
+        working-directory: aether-vscodex/web
+        run: |
+          npm ci
+          npm run build
 
       - name: Install & build
         working-directory: frontend
@@ -93,6 +101,71 @@ jobs:
           if-no-files-found: error
           retention-days: 1
 
+  vscodex:
+    name: Build VS Code Codex extension
+    needs: preflight
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+          cache-dependency-path: |
+            aether-vscodex/package-lock.json
+            aether-vscodex/web/package-lock.json
+            aether-vscodex/vscode-extension/package-lock.json
+
+      - name: Install module test dependencies
+        working-directory: aether-vscodex
+        run: npm ci
+
+      - name: Build the embedded Web UI
+        working-directory: aether-vscodex/web
+        run: |
+          npm ci
+          npm run build
+
+      - name: Install extension dependencies
+        working-directory: aether-vscodex/vscode-extension
+        run: npm ci
+
+      - name: Check and compile the extension
+        working-directory: aether-vscodex/vscode-extension
+        run: |
+          npm run check
+          npm run build
+
+      - name: Run module tests
+        working-directory: aether-vscodex
+        run: npm test
+
+      - name: Run Web UI tests
+        working-directory: aether-vscodex/web
+        run: npm test
+
+      - name: Package VSIX
+        working-directory: aether-vscodex/vscode-extension
+        shell: bash
+        run: |
+          set -euo pipefail
+          version="$(node -p "require('./package.json').version")"
+          npx --yes @vscode/vsce package --no-update-package-json --allow-missing-repository
+          source_vsix="codex-remote-collab-${version}.vsix"
+          test -f "${source_vsix}"
+          mv "${source_vsix}" "aether-vscodex-${version}.vsix"
+          unzip -l "aether-vscodex-${version}.vsix" | grep 'extension/node_modules/ws/index.js' >/dev/null
+
+      - name: Upload VSIX artifact
+        uses: actions/upload-artifact@v5
+        with:
+          name: aether-vscodex-vsix
+          path: aether-vscodex/vscode-extension/aether-vscodex-*.vsix
+          if-no-files-found: error
+          retention-days: 7
+
   build:
     name: Build ${{ matrix.name }}
     needs: preflight
@@ -299,7 +372,7 @@ jobs:
 
   github-release:
     name: GitHub Release assets
-    needs: [preflight, docker, package]
+    needs: [preflight, docker, package, vscodex]
     if: needs.preflight.outputs.publish == 'true'
     runs-on: ubuntu-latest
     steps:
@@ -309,6 +382,12 @@ jobs:
           name: release-assets
           path: release-assets
 
+      - name: Download VSIX artifact
+        uses: actions/download-artifact@v5
+        with:
+          name: aether-vscodex-vsix
+          path: release-assets
+
       - name: Delete stale draft releases for tag
         env:
           GH_TOKEN: ${{ github.token }}
@@ -340,3 +419,4 @@ jobs:
             release-assets/*.tar.gz
             release-assets/SHA256SUMS
             release-assets/install.sh
+            release-assets/*.vsix