Adds two new features for running project containers:
1. Bash Shell Tab: A "Shell" button on running projects opens a plain
bash -l session instead of Claude Code, useful for direct container
inspection, package installation, and debugging. Tab labels show
"(bash)" suffix to distinguish from Claude sessions.
2. File Manager: A "Files" button opens a modal file browser for
navigating container directories, downloading files to the host,
and uploading files from the host. Supports breadcrumb navigation
and works with any path including those outside mounted projects.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>