Show actual disk size instead of size spec in resize command

[gwpl]

Summary

AI Agent with Greg: We resized a droplet with --no-disk to keep the option to scale back down, then ran dropkit resize again and saw "Disk: 80 GB" — which made us briefly question our own sanity. Turns out the resize display was reading the size spec instead of the actual disk. Reality check restored. 🔍💾

The bug: After a --no-disk resize (e.g., s-1vcpu-1gb → s-2vcpu-4gb), the resize command showed disk from droplet["size"]["disk"] (80 GB — what the size tier offers) instead of droplet["disk"] (25 GB — what the droplet actually has).

The fix: Read from droplet["disk"] (actual allocation). When actual disk differs from size spec, show an inline hint so the situation is immediately clear:

Current Size: s-2vcpu-4gb
  vCPUs:     2
  Memory:    4096 MB
  Disk:      25 GB (size spec: 80 GB, disk was not resized)
  Price:     $24.00/month

vs. previously misleading:

Current Size: s-2vcpu-4gb
  vCPUs:     2
  Memory:    4096 MB
  Disk:      80 GB   ← wrong! actual disk is 25 GB
  Price:     $24.00/month

This matters most for users doing temporary CPU/RAM scale-ups who need to confirm their disk is still at the original size before scaling back down.

Test plan

• uv run ruff check dropkit/main.py — passed
• uv run ruff format --check dropkit/main.py — passed
• uv run ty check dropkit/main.py — passed
• uv run pytest tests/ -v — 288 passed (1 pre-existing failure in test_rename unrelated to this change)
• Manual test: dropkit resize <name> after a --no-disk resize — verify actual disk shown with hint
• Manual test: dropkit resize <name> on a droplet where disk matches spec — verify no hint shown

🤖 Generated with Claude Code — your friendly AI that believes in showing users the truth, the whole truth, and nothing but the disk truth

Co-Authored-By: Claude Opus 4.6 (1M context) noreply@anthropic.com

[gwpl]

AI Assistant:
👋 Hi! This one comes from the Claude + Greg debugging duo. We stared at a disk size that was lying to our face after a no-disk resize, and decided that was unacceptable — dropkit should report what the disk actually is, not what the size spec wishes it were. Trust but verify, especially your storage layer. Feedback welcome!

[ret2libc]

Nice!