Add offline RefreshPrices, fix sync bugs, implement auto-restart

- Implement RefreshPrices for local-first mode
  - Update prices from local_components.current_price cache
  - Graceful degradation when component not found
  - Add PriceUpdatedAt timestamp to LocalConfiguration model
  - Support both authenticated and no-auth price refresh

- Fix sync duplicate entry bug
  - pushConfigurationUpdate now ensures server_id exists before update
  - Fetch from LocalConfiguration.ServerID or search on server if missing
  - Update local config with server_id after finding

- Add application auto-restart after settings save
  - Implement restartProcess() using syscall.Exec
  - Setup handler signals restart via channel
  - Setup page polls /health endpoint and redirects when ready
  - Add "Back" button on setup page when settings exist

- Fix setup handler password handling
  - Use PasswordEncrypted field consistently
  - Support empty password by using saved value

- Improve sync status handling
  - Add fallback for is_offline check in SyncStatusPartial
  - Enhance background sync logging with prefixes

- Update CLAUDE.md documentation
  - Mark Phase 2.5 tasks as complete
  - Add UI Improvements section with future tasks
  - Update SQLite tables documentation

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

web/templates/setup.html

@@ -61,6 +61,12 @@
                 <div id="status" class="hidden p-3 rounded-md text-sm"></div>
 
                 <div class="flex space-x-3 pt-4">
+                    {{if .Settings}}
+                    <a href="/"
+                       class="flex-1 px-4 py-2 bg-gray-100 text-gray-700 rounded-md hover:bg-gray-200 transition text-center">
+                        Назад
+                    </a>
+                    {{end}}
                     <button type="button" onclick="testConnection()"
                             class="flex-1 px-4 py-2 bg-gray-100 text-gray-700 rounded-md hover:bg-gray-200 transition">
                         Проверить
@@ -122,6 +128,34 @@
             }
         }
 
+        async function checkServerReady() {
+            let attempts = 0;
+            const maxAttempts = 30; // 30 seconds max
+
+            const checkInterval = setInterval(async () => {
+                attempts++;
+                try {
+                    const resp = await fetch('/health', { method: 'GET' });
+                    const data = await resp.json();
+
+                    // Check if we're out of setup mode
+                    if (data.status === 'ok') {
+                        clearInterval(checkInterval);
+                        showStatus('✓ Приложение запущено! Перенаправление...', 'success');
+                        setTimeout(() => {
+                            window.location.href = '/';
+                        }, 1000);
+                    }
+                } catch (e) {
+                    // Server still restarting, continue polling
+                    if (attempts >= maxAttempts) {
+                        clearInterval(checkInterval);
+                        showStatus('Сервер не отвечает. Обновите страницу вручную.', 'error');
+                    }
+                }
+            }, 1000); // Check every second
+        }
+
         document.getElementById('setup-form').addEventListener('submit', async function(e) {
             e.preventDefault();
             showStatus('Сохранение настроек...', 'info');
@@ -136,9 +170,12 @@
                 const data = await resp.json();
 
                 if (data.success) {
-                    showStatus(data.message + ' Перенаправление...', 'success');
+                    showStatus('✓ ' + data.message, 'success');
+                    // Wait for restart and redirect to home
                     setTimeout(() => {
-                        window.location.href = '/';
+                        showStatus('✓ Настройки сохранены. Проверка подключения...', 'success');
+                        // Poll until server is back
+                        checkServerReady();
                     }, 2000);
                 } else {
                     showStatus(data.error, 'error');