feat: Add session management and global Claude terminal

Phase 1 - Accurate study status detection:
- Add is_optimization_running() to check for active processes
- Add get_accurate_study_status() with proper status logic
- Status now: not_started, running, paused, completed
- Add "paused" status styling (orange) to Home page

Phase 2 - Global Claude terminal:
- Create ClaudeTerminalContext for app-level state
- Create GlobalClaudeTerminal floating component
- Terminal persists across page navigation
- Shows green indicator when connected
- Remove inline terminal from Dashboard

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

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

atomizer-dashboard/frontend/vite.config.ts

@@ -10,7 +10,7 @@ export default defineConfig({
     strictPort: false, // Allow fallback to next available port
     proxy: {
       '/api': {
-        target: 'http://127.0.0.1:8001', // Use 127.0.0.1 instead of localhost
+        target: 'http://127.0.0.1:8000', // Use 127.0.0.1 instead of localhost
         changeOrigin: true,
         secure: false,
         ws: true,