…cies

Add ProxyGroup model, service, and CRUD API handlers with full
test coverage for host grouping functionality.

- Add ProxyGroup model with UUID, name, description, color fields
- Add ProxyGroupID FK and ProxyGroup preload to ProxyHost
- Add ProxyGroupService with Create/List/GetByUUID/Update/Delete
- Add ProxyGroupHandler with GET/POST/PUT/DELETE routes
- Extend ProxyHostHandler to resolve proxy_group_id by UUID or uint
- AutoMigrate ProxyGroup before ProxyHost in routes.go
- Add 22 tests across service, handler, and preload integration

Closes #254

Add ProxyGroups API client with TanStack Query hooks
Add ProxyGroupBadge and ProxyGroupForm components
Integrate proxy group selection into ProxyHosts page
Add locale strings (de, en, es, fr, zh) for proxy group feature
Add frontend unit tests for API client, components, and hooks
Add E2E Playwright spec for proxy group management workflows
Update ProxyHosts tests to reflect proxy group column addition
Update vitest config for new component test coverage

Add proxy group column and assignment UI to ProxyHosts table
Update proxyHosts API client to include group_id field
Add proxy group locale keys for all supported languages (de, en, es, fr, zh)
Update ProxyHosts tests to cover proxy group column and filtering
Extend vitest config for expanded proxy hosts test coverage

…st model

…nced drag-and-drop functionality

- Hosts can be dragged individually or in bulk (multi-select) into any group
  section or the ungrouped section, updating their group membership server-side
- Backend exposes a single PUT /proxy-hosts/bulk-update-group endpoint that
  updates all dragged hosts in one request and calls Caddy ApplyConfig once
  instead of N times, keeping Caddy config consistent and avoiding thundering
  herd
- Optimistic UI update rolls back on network failure so the list never shows
  stale state after a failed drag
- Screen reader users receive live announcements on drag start, drag over,
  drop, and cancel via @dnd-kit accessibility.announcements, satisfying
  WCAG 2.2 §4.1.3
- Toast notifications correctly show success (with i18next pluralization count
  matching dragged host count) or error (including full-failure case that was
  previously silent)
- Group name helper exposed in ProxyHosts for accessibility announcements
  alongside the existing host name helper
- All five locale files updated with DnD announcement and status strings
- New DnD hook, drop zone, drag handle, and bulk API encapsulated in separate
  files to keep ProxyHosts.tsx focused on layout and wiring
- 6 unit tests for BulkUpdateGroup handler; 5 unit tests for useProxyGroupDnD
  hook covering happy path, no-op same-group, rollback, partial success, and
  multi-select drag
- Backend patch coverage 90.5%, frontend patch coverage 95.6%, overall 92%

…eration tests

- Five vi.mock() calls added for useSecurityHeaders and useProxyGroups in the
  bulk-operation test files were missing trailing semicolons, causing CodeQL to
  flag them under the automatic-semicolon-insertion rule
- Every other vi.mock() statement in those files has an explicit semicolon, so
  the linter correctly flagged the inconsistency
- No test logic was changed; the fix is purely syntactic to satisfy static analysis

- The react-i18next mock was returning raw keys verbatim, causing tests that
  look for human-readable strings like "Create Group" to fail against the
  rendered key "proxyGroups.createGroup"
- Expanded the mock to return proper translated strings for all keys used by
  the component, including interpolated values for the color preset aria-label
- No component logic changed; this is a test-only correction

Adding the Group column in the proxy groups feature pushed total column
widths to 112%, causing the right side of each row to overflow and get
clipped. Redistributed width from Name, Domain, Forward, SSL, and
Features columns to bring the total back to 100%.