fix: fix login image (#10355)

# Which Problems Are Solved

The broken login image is fixed.

# How the Problems Are Solved

The most important learnings from
https://github.com/zitadel/zitadel/pull/10318 are applied:
- Path in entrypoint is fixed: `exec node /runtime/apps/login/server.js`
- .dockerignore is updated so CSS styles are built into the image
- `source: .` is passed to the docker-bake action. Without this,
docker-bake builds from a remote context, which seems to be slow and not
updated on new PR commits. Looks like the bake action uploads an
artifact that [conflicts with the compile
workflow](https://github.com/zitadel/zitadel/actions/runs/16620417216/job/47023478437).
Therefore, a pattern is added to the compile workflow so only relevant
artifacts are selected.

.github/workflows/compile.yml

@@ -77,6 +77,7 @@ jobs:
       - uses: actions/download-artifact@v4
         with:
           path: executables
+          pattern: 'zitadel-*-*'
       - name: move files one folder up
         run: mv */*.tar.gz . && find . -type d -empty -delete
         working-directory: executables

.github/workflows/login-container.yml

@@ -55,6 +55,7 @@ jobs:
         env:
           NODE_VERSION: ${{ inputs.node_version }}
         with:
+          source: .
           push: true
           provenance: true
           sbom: true