refactor: rename swift → cortex in code and documentation

Complete rename of "swift" terminology to "cortex" across the codebase:

Code Changes:
- Rename directories: lib/swift → lib/cortex, components/swift → components/cortex
- Rename API routes: /api/swift/* → /api/cortex/*
- Rename page routes: /epd/swift → /epd/cortex
- Rename store: swift-store.ts → cortex-store.ts

Type Renames:
- SwiftIntent → CortexIntent
- SwiftStore → CortexStore
- useSwiftStore → useCortexStore
- SwiftContext → CortexContext
- useSwiftVoice → useCortexVoice

Documentation Updates (docs/intent/):
- Safety Net → Nudge (Layer 3 rename)
- SafetySuggestion → NudgeSuggestion
- evaluateSafetyNet → evaluateNudge
- SWIFT_* feature flags → CORTEX_*
- All path references updated to match new structure

Files affected: 47 files, ~700 lines changed

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

middleware.ts

@@ -88,7 +88,7 @@ export async function middleware(request: NextRequest) {
   // Helper: get preferred interface redirect path
   const getPreferredPath = () => {
     const preference = user?.user_metadata?.preferred_interface
-    return preference === 'swift' ? '/epd/swift' : '/epd/clients'
+    return preference === 'cortex' ? '/epd/cortex' : '/epd/clients'
   }
 
   // Redirect to preferred interface if authenticated and trying to access login