fix: simplify dockerfile by moving directory creation to entrypoint

Removes code-server and vscode-server directory creation from Dockerfile
to avoid permission issues during multi-platform builds.

These directories are now only created in entrypoint.sh which:
- Runs as root
- Creates directories with correct ownership
- Runs on every container start

This approach is more reliable as entrypoint.sh can use mkdir -p and
chown without permission conflicts that occur during image build.

Fixes multi-platform build failures on arm64 architecture.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: mohsin-wiser

.devcontainer/Dockerfile

@@ -177,10 +177,10 @@ RUN rm -rf /tmp/backend /tmp/root /tmp/frontend
 # Pre-create user directories to avoid permission issues in post-create
 USER vscode
 RUN mkdir -p ~/.m2/repository ~/.m2/wrapper/dists ~/.npm ~/.cache/ms-playwright \
-    && mkdir -p ~/.local/share && chmod 755 ~/.local \
-    && mkdir -p ~/.local/share/code-server ~/.config/code-server \
-    && mkdir -p ~/.vscode-server/bin ~/.vscode-server/extensions \
-    && chmod -R 755 ~/.m2 ~/.npm ~/.cache ~/.local ~/.config ~/.vscode-server
+    && chmod -R 755 ~/.m2 ~/.npm ~/.cache
+
+# Note: code-server and vscode-server directories are created in entrypoint.sh
+# as root to avoid permission issues during image build
 
 # Reset working directory and user
 USER root