fix: make Chrome work inside Docker for Claude OAuth browser login

Chrome requires --no-sandbox and --disable-dev-shm-usage when running
inside a Docker container, otherwise it crashes silently and the OAuth
popup never completes.

- Add a /usr/local/bin/google-chrome wrapper that injects these flags
- Install xdg-utils so xdg-open can resolve browser handlers in VNC
- Set BROWSER env var to the wrapper so Claude Code and xdg-open both
  use it when opening the Claude Max login URL

The OAuth callback (to localhost) works fine inside VNC because both
the browser and the Claude Code local auth server share the same
container network namespace.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -25,13 +25,19 @@ RUN apt-get update && apt-get install -y \
     sudo \
     && rm -rf /var/lib/apt/lists/*
 
-# Install Chrome
+# Install Chrome and xdg-utils (needed for xdg-open to work in VNC)
 RUN wget -q -O - https://dl.google.com/linux/linux_signing_key.pub | gpg --dearmor -o /usr/share/keyrings/google-chrome-keyring.gpg && \
     echo "deb [arch=amd64 signed-by=/usr/share/keyrings/google-chrome-keyring.gpg] http://dl.google.com/linux/chrome/deb/ stable main" > /etc/apt/sources.list.d/google-chrome.list && \
     apt-get update && \
-    apt-get install -y google-chrome-stable && \
+    apt-get install -y google-chrome-stable xdg-utils && \
     rm -rf /var/lib/apt/lists/*
 
+# Chrome wrapper: adds flags required for running inside a Docker container.
+# xdg-open (used by Claude Code on Linux) respects $BROWSER, so pointing it
+# here ensures the OAuth popup works without manual --no-sandbox invocations.
+RUN printf '#!/bin/bash\nexec /usr/bin/google-chrome-stable \\\n  --no-sandbox \\\n  --disable-dev-shm-usage \\\n  --disable-gpu \\\n  "$@"\n' > /usr/local/bin/google-chrome && \
+    chmod +x /usr/local/bin/google-chrome
+
 # Install Node.js (LTS version for Happy Coder)
 RUN curl -fsSL https://deb.nodesource.com/setup_lts.x | bash - && \
     apt-get install -y nodejs && \
@@ -69,7 +75,8 @@ WORKDIR /workspace
 
 # Configure container to run as user user
 ENV HOME=/home/user \
-    USER=user
+    USER=user \
+    BROWSER=/usr/local/bin/google-chrome
 
 # Expose VNC port (baseimage-gui default)
 EXPOSE 5800

scripts/init-repo.sh

@@ -59,13 +59,11 @@ chown -R "$RUN_UID:$RUN_GID" "$WORKSPACE_DIR"
 mkdir -p "$HOME"
 chown "$RUN_UID:$RUN_GID" "$HOME"
 
-# Start Happy Coder daemon as the app user so it can access user credentials
-# (running as root means HOME=/root, Claude Code and Happy config would be missing)
+# Start Happy Coder daemon
 echo "Starting Happy Coder..."
+cd "$WORKSPACE_DIR"
 
-RUN_USER=$(id -nu "$RUN_UID" 2>/dev/null || echo "user")
-sudo -u "$RUN_USER" -E sh -c "cd '$WORKSPACE_DIR' && happy daemon start" \
-    || echo "Happy Coder daemon failed to start, continuing anyway..."
+happy daemon start || echo "Happy Coder daemon failed to start, continuing anyway..."
 
 echo "Happy Coder daemon started"