Implements Task 5 of Phase 3 (Stores + Router + App Shell): - Replace App.svelte placeholder with full app shell component - Add sidebar navigation with project selector and main nav links - Implement view routing with Placeholder components for all routes - Initialize WebSocket connection and dispatch events to graph/agents stores - Use flexbox layout with fixed sidebar (240px) and scrollable main content - Maintain dark theme with colors #12122a (sidebar) and #1a1a2e (main) Also fixes Svelte 5 module-level $derived export issue: - Convert selectedProject to getSelectedProject() function - Convert goalNodes to getGoalNodes() function - Convert tasksByStatus to getTasksByStatus() function All files pass TypeScript check and build succeeds with no errors. All router tests pass (14/14) and WebSocket tests pass (14/14). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>