Add slash command autocomplete for CLI (v0.4.1)

[k29]

Implement real-time autocomplete suggestions for slash commands in the interactive CLI. When users type "/" they see all available commands with descriptions displayed below the input line in a dimmed style.

Features:

• Suggestions appear immediately when "/" is typed (no Tab required)
• Filter commands by name as user types (e.g., "/sk" shows skill/skills)
• Up/Down arrows navigate suggestions with visual highlighting
• Tab or Enter populates the selected command without executing
• Second Enter executes the populated command
• Escape dismisses suggestions
• Backspace updates filtering or clears suggestions

Implementation uses rustyline's ConditionalEventHandler for keyboard intercepts combined with crossterm for rendering the suggestion overlay below the input line.

Bumps tycode-cli version to 0.4.1.

[tigy32]

If I'm using arrows or typing in item im seeing the old version jump up my screen instead of disappearing. Maybe we need to push redraw those 10 lines or something?

> /clear - Clear the conversation history
  /context - Show what files would be included in the AI context
  /fileapi - Set the file modification API (patch or find-replace)
  /model - Set the AI model for all agents
  /trace - Enable/disable trace logging to .tycode/trace
  /settings - Display current settings and configuration
  /cost - Show session token usage and estimated cost, or set model cost limit
  /help - Show this help message
  /models - List available AI models
  /provider - List, switch, or add AI providers
> /











> /clear - Clear the conversation history
  /context - Show what files would be included in the AI context
> /c



> /cl