v1.6.30

• chore: bump version to 1.6.30 [skip ci]
• fix(build-release): make release builder work on Windows/Git Bash
• feat(dns): give-this-a-subdomain + all-managed-records view (Phase 4 backend)
• feat(dns): per-base-domain subdomain modes — wildcard vs per-site (Phase 3)
• feat(dns): "Changes to your Cloudflare" UI — activity feed + zone mirror (Phase 2 frontend)
• feat(dns): change log + admin notice on failure (Phase 2 backend)
• feat(dns): ownership ledger + never-touch-foreign guard + zone mirror (Phase 1)
• feat(dns): unify Cloudflare credentials behind one connection + shared client
• fix(build-release): make release builder work on Windows/Git Bash
• feat: add dismissible system notices for common misconfigurations
• Normalize emails, add panel_origin & domain-aware URLs