feat: v0.5.0 - provider icon actions, duplicate & connectivity test, dashboard chart fixes
- ProviderList: icon buttons (edit/copy/test/delete) via lucide-react, speed-test badge before enable/switch button
- Duplicate provider: deep-copy provider + models as xxx-copy
- test_connectivity command (cc-switch semantics: GET base_url, any HTTP response = reachable), latency badge green/orange/red, auto-dismiss 6s
- Dashboard: daily bars anchored to panel bottom, Card flex height fix (heatmap stays content-height)