[UX] Progress indicators for all operations

[mikejmorgan-ai]

Problem

Commands run silently. Users don't know if it's working or frozen.

Solution

Rich progress output:

$ cortex install ml-stack
🔍 Analyzing request...
🧠 AI determining packages... (2s)
📋 Planning installation:
   → pytorch (2.1.0)
   → cuda-toolkit-12-3
   → cudnn
   → jupyter
   
📦 Installing... ████████████░░░░ 75% (pytorch)
✓ Installed 4 packages in 3m 42s

Requirements

• Spinner for AI thinking phase
• Package list before install begins
• Progress bar for apt operations (parse apt output)
• Time elapsed + ETA
• Clear success/failure summary
• Use rich or similar library for terminal UI

## Bounty: $15 now (+$15 match after funding)

Total: $30 when we close our funding round.