Fix Claude auth persistence and improve devcontainer user configuration

- Add bind mounts for .claude directory and .claude.json file to persist Claude authentication across container rebuilds
- Switch from vscode to ubuntu user (UID 1000) to resolve shell history permission issues
- Update volume mounts to use ubuntu user paths
- Remove old Docker volumes that had incorrect ownership

Author: wassertim

docker-compose.yml

@@ -10,6 +10,8 @@ services:
       - devcontainer-shell-history:/home/ubuntu/.shell_history
       - claude-auth:/home/ubuntu/.config/claude
       - github-cli-auth:/home/ubuntu/.config/gh
+      - ${PWD}/.claude:/home/ubuntu/.claude:cached
+      - ${HOME}/.claude.json:/home/ubuntu/.claude.json:cached
     working_dir: /workspace
     command: sleep infinity
     depends_on: