chore: add dogfood template for coder/vscode-coder development (#24306)

Add a new template to dev.coder.com for developing the coder/vscode-coder
VS Code extension.

The Docker image is based on node:24-slim (pinned by digest) with git, gh
CLI, dbus, and sudo. Electron system libraries are installed at workspace
startup via playwright install-deps so they stay in sync with the project's
Electron version without Dockerfile changes.

The template includes IDE selection (VS Code Desktop, code-server, Cursor,
etc.), filebrowser, dotfiles, and Claude Code for AI tasks.

.github/workflows/dogfood.yaml

@@ -125,6 +125,19 @@ jobs:
           tags: "codercom/oss-dogfood:${{ steps.docker-tag-name.outputs.tag }},codercom/oss-dogfood:26.04"
         if: matrix.image-version == '26.04'
 
+      - name: Build and push vscode-coder image
+        uses: depot/build-push-action@5f3b3c2e5a00f0093de47f657aeaefcedff27d18 # v1.17.0
+        with:
+          project: b4q6ltmpzh
+          token: ${{ secrets.DEPOT_TOKEN }}
+          buildx-fallback: true
+          context: "{{defaultContext}}:dogfood/vscode-coder"
+          pull: true
+          save: true
+          push: ${{ github.ref == 'refs/heads/main' }}
+          tags: "codercom/oss-dogfood-vscode-coder:${{ steps.docker-tag-name.outputs.tag }},codercom/oss-dogfood-vscode-coder:latest"
+        if: matrix.image-version == '22.04'
+
       - name: Build Nix image
         run: nix build .#dev_image
         if: matrix.image-version == 'nix'
@@ -184,6 +197,10 @@ jobs:
           terraform init
           terraform validate
           popd
+          pushd dogfood/vscode-coder
+          terraform init
+          terraform validate
+          popd
 
       - name: Get short commit SHA
         if: github.ref == 'refs/heads/main'