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>

components/cortex/command-center/command-center.tsx

@@ -0,0 +1,123 @@
+'use client';
+
+/**
+ * Command Center (v3.0)
+ *
+ * Main container for the Cortex interface.
+ * Split-screen layout: Chat Panel (40%) | Artifact Area (60%)
+ *
+ * Layout specs:
+ * - Context Bar: 48px (h-12) - UNCHANGED
+ * - Split container: flex-1 (fills remaining space)
+ *   - Chat Panel: 40% width (desktop), 100% (mobile)
+ *   - Artifact Area: 60% width (desktop), 100% (mobile)
+ *
+ * Epic: E1 (Foundation)
+ * Stories: E1.S2 (Split-screen layout), E1.S3 (Placeholders), E1.S4 (Responsive)
+ */
+
+import { useEffect, useCallback, useRef } from 'react';
+import { useCortexStore } from '@/stores/cortex-store';
+import { ContextBar } from './context-bar';
+import { OfflineBanner } from './offline-banner';
+import { ChatPanel } from '../chat/chat-panel';
+import { ArtifactArea } from '../artifacts/artifact-area';
+import { getArtifactTitle } from '../artifacts/artifact-container';
+import { routeIntentToArtifact } from '@/lib/cortex/action-parser';
+
+export function CommandCenter() {
+  const { closeAllArtifacts, openArtifacts, openArtifact, pendingAction, setPendingAction } = useCortexStore();
+  const inputRef = useRef<HTMLInputElement>(null);
+
+  // Global keyboard shortcuts
+  const handleKeyDown = useCallback(
+    (e: KeyboardEvent) => {
+      // Escape: close all artifacts
+      if (e.key === 'Escape' && openArtifacts.length > 0) {
+        e.preventDefault();
+        closeAllArtifacts();
+      }
+
+      // Cmd/Ctrl + K: focus input (chat input in v3.0)
+      if ((e.metaKey || e.ctrlKey) && e.key === 'k') {
+        e.preventDefault();
+        inputRef.current?.focus();
+      }
+    },
+    [openArtifacts, closeAllArtifacts]
+  );
+
+  useEffect(() => {
+    window.addEventListener('keydown', handleKeyDown);
+    return () => window.removeEventListener('keydown', handleKeyDown);
+  }, [handleKeyDown]);
+
+  // E3.S6 + E4.S2: Handle pending actions from chat (artifact opening)
+  useEffect(() => {
+    if (!pendingAction) return;
+
+    console.log('[CommandCenter] Processing pending action:', pendingAction);
+
+    // Check if action has artifact data
+    if (pendingAction.artifact) {
+      const { type, prefill } = pendingAction.artifact;
+
+      // Generate title for the artifact
+      const title = getArtifactTitle(type, prefill);
+
+      console.log('[CommandCenter] Opening artifact:', type, title);
+
+      // Open the artifact (E4.S2 - new artifact system)
+      openArtifact({
+        type,
+        prefill,
+        title,
+      });
+
+      setPendingAction(null);
+      return;
+    }
+
+    const routedArtifact = routeIntentToArtifact(
+      pendingAction.intent,
+      pendingAction.entities,
+      pendingAction.confidence
+    );
+
+    if (routedArtifact) {
+      console.log('[CommandCenter] Routing action to artifact:', routedArtifact.type);
+      openArtifact({
+        type: routedArtifact.type,
+        prefill: routedArtifact.prefill,
+        title: routedArtifact.title,
+      });
+    } else {
+      console.log('[CommandCenter] Action has no artifact, skipping');
+    }
+
+    setPendingAction(null);
+  }, [pendingAction, openArtifact, setPendingAction]);
+
+  return (
+    <div className="flex flex-col h-screen overflow-hidden">
+      {/* Offline Banner */}
+      <OfflineBanner />
+
+      {/* Context Bar - 48px (unchanged) */}
+      <ContextBar />
+
+      {/* Split-screen container - flex-1 */}
+      <div className="flex-1 flex overflow-hidden">
+        {/* Chat Panel - 40% (desktop), 100% (mobile) */}
+        <div className="w-full lg:w-[40%] border-r border-slate-200 flex flex-col">
+          <ChatPanel />
+        </div>
+
+        {/* Artifact Area - 60% (desktop), hidden on mobile */}
+        <div className="hidden lg:flex lg:w-[60%] flex-col">
+          <ArtifactArea />
+        </div>
+      </div>
+    </div>
+  );
+}