🤖 Add Storybook stories for tool messages and custom FileRead renderer

- Add comprehensive ToolMessage stories for bash and file_edit tools
- Create custom FileReadToolCall component with compact collapsed view
- Display file read as: 🔍 <file path> ~<tokens>
- Add file metadata (size, lines, modified time) on expand
- Add 13 tool message story variants covering all states
- Wire up FileReadToolCall in ToolMessage router

Generated with `cmux`

Author: ammario