Preserve native Codex history and add configurable cross-model compression

Separate encrypted reasoning from actual compaction, stop migration after native return, and retain full history and recent exchanges. Add typed settings, Gemini fallback, verified provider windows, bounded summaries and durable concurrent checkpoints.

Validation: 245 bridge tests plus focused concurrency tests; 71 settings/connection tests; 66 supplementary tests; TypeScript checks; renderer and Electron bundles; real primary/native/fallback summary probes and 700K input acceptance.

apps/desktop/src/app/settings/codex-link-settings.tsx

@@ -11,6 +11,7 @@ import { notifyError } from '@/store/notifications'
 import type { CodexLinkPatch, CodexLinkStatus } from '../../../electron/codex-link-types'
 
 import { EmptyState, ListRow, ListRowSkeleton, SettingsContent, SettingsSection } from './primitives'
+import { CompressionSettingsView } from './compression-settings'
 
 type Tone = 'muted' | 'ok' | 'warn'
 
@@ -229,6 +230,7 @@ export function CodexLinkSettings() {
           {copy.restartNote}
         </p>
       </SettingsSection>
+      <CompressionSettingsView />
     </SettingsContent>
   )
 }