feat: improve UI contrast, dark mode, dialog sizing, color coherence, and add table sorting

- Fix dialog scrollability (flex layout + max-h-[90dvh]) and increase L4 dialog to lg width
- Add styled enable card to L4 dialog matching proxy host pattern
- Unify section colors across proxy host and L4 dialogs (cyan=LB, emerald=DNS, violet=upstream DNS, rose=geo, amber=mTLS)
- Improve light mode contrast: muted-foreground oklch 0.552→0.502, remove opacity modifiers on secondary text
- Improve dark mode: boost muted-foreground to 0.85, increase border opacity 10%→16%, input 15%→20%
- Add bg-card to DataTable wrapper and bg-muted/40 to table headers for surface hierarchy
- Add semantic badge variants (success, warning, info, muted) and StatusChip dark mode fix
- Add server-side sortable columns to Proxy Hosts and L4 Proxy Hosts (name, upstream, status, protocol, listen)
- Add sortKey to DataTable Column type with clickable sort headers (ArrowUp/Down indicators, URL param driven)
- Fix E2E test selectors for shadcn UI (label associations, combobox roles, dropdown menus, mobile drawer)
- Add htmlFor/id to proxy host form fields and aria-labels to select triggers for accessibility
- Add sorting E2E tests for both proxy host pages

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

tests/e2e/functional/ssl-redirect.spec.ts

@@ -33,7 +33,7 @@ test.describe.serial('SSL Redirect (ssl_forced)', () => {
 
     await page.getByRole('button', { name: /^create$/i }).click();
     await expect(page.getByRole('dialog')).not.toBeVisible({ timeout: 15_000 });
-    await expect(page.getByText('Functional SSL Redirect Test')).toBeVisible({ timeout: 10_000 });
+    await expect(page.getByRole('table').getByText('Functional SSL Redirect Test')).toBeVisible({ timeout: 10_000 });
 
     await waitForRoute(DOMAIN);
   });