fix(cli): fail fast when k3d is missing (CLEAN-43)

[maksymhryzodub-prog]

Summary

• ranch dev now requires k3d before any image pull (compose needs the external k3d-ranch network).
• Install hint is OS-specific: winget/choco/scoop on Windows, brew on macOS, k3d install script on Linux.
• docker-up.sh inspects k3d-ranch before compose up, so postgres/minio are not downloaded first.
• ranch dev --no-k3d creates a dummy k3d-ranch network so compose can still start without a cluster.

Test plan

• cd cli && bun test src/utils/k3d.test.ts
• Without k3d: ranch dev exits immediately with the Windows install hint (no image pull)
• With k3d: existing ranch dev still creates the cluster then compose

Fixes CLEAN-43