Add TUI

[alpaim]

Changes Made

1. Cargo.toml

Added TUI dependencies and updated vecbox-core:

• ratatui = "0.30.0" - Terminal UI framework for building interactive interfaces
• crossterm = "0.28" - Cross-platform terminal manipulation library
• Updated vecbox-core from v0.1.0 to v0.1.1

2. src/tui.rs

New TUI module providing an interactive terminal wizard:

• AppState - Holds server configuration (repo, quant, host, port, pixels settings)
• Step enum - Wizard steps: Welcome, ModelSelection, QuantSelection, ServerConfig, Summary, Running
• State - Manages current wizard state and user input
• run_wizard() - Entry point for interactive configuration wizard
• Multi-step wizard flow for selecting model, quantization, and server settings
• Keyboard navigation with arrow keys, Enter to confirm, Esc to go back
• Live log display when server is running
• Graceful terminal cleanup on exit (Ctrl+C support)

3. src/cli.rs

Extended CLI with TUI mode:

• New tui subcommand to launch interactive terminal wizard
• Refactored argument structure for cleaner command handling

4. src/main.rs

Integrated TUI into application entry point:

• Routes to run_wizard() when tui subcommand is used
• Added TUI module declaration

5. src/api/server.rs

Updated for TUI integration:

• Modified server startup to work with TUI state management
• Added atomic flag support for graceful server shutdown from TUI

6. src/api/mod.rs

Updated exports for TUI integration