fix(opencode): ensure proper installation and workspace setup

- Add --unsafe-perm to npm install for global package installation
- Add cd /workspace to /root/.bashrc so terminal opens in repo directory
- Start container process in /workspace directory
- Use exec for proper signal handling

Quality gates: code review

apps/api/src/main.py

@@ -169,10 +169,11 @@ services:
       - "3000:3000"
     command: >
       sh -c "apt-get update && apt-get install -y git &&
-             npm install -g opencode-ai &&
-             mkdir -p /workspace &&
+             npm install -g opencode-ai --unsafe-perm &&
+             echo 'cd /workspace' >> /root/.bashrc &&
              echo 'OpenCode installed. Run: opencode' &&
-             tail -f /dev/null"
+             cd /workspace &&
+             exec tail -f /dev/null"
     stdin_open: true
     tty: true
     restart: unless-stopped