refactor: unify docker deployment and restructure frontend architecture

This commit implements a unified Docker deployment strategy, moving from separate frontend and backend images to a single, multi-stage build image containing both services. It also introduces a major reorganization of the frontend directory structure and simplifies the environment configuration.

Key changes:
- **Deployment**: Added a multi-stage `Dockerfile` and `docker-entrypoint.sh` to package the Go backend and Nginx-served frontend into a single container.
- **CI/CD**: Updated GitHub Actions workflows (`ci-cd.yml`, `release.yml`) to build and push the new unified image instead of separate ones.
- **Frontend Refactor**: Reorganized `frontend/src/pages` into a domain-driven directory structure (e.g., `auth/`, `admin/`, `content/`, `communication/`, `productivity/`, `settings/`, `misc/`).
- **Configuration**: Simplified `.env.example` and updated `docker-compose.yml` to reflect the unified service model and single host port.
- **Cleanup**: Removed deprecated `docker-compose.demo.yml`, `docker-compose.prod.yml`, and various unused frontend components and services.
- **Backend**: Refactored configuration loading to use exported `GetDurationEnv` for better consistency.

frontend/src/App.tsx

@@ -3,33 +3,33 @@ import { QueryClient, QueryClientProvider } from '@tanstack/solid-query'
 import { Layout } from '@/components/layout/Layout'
 import { ProtectedRoute } from '@/components/ProtectedRoute'
 import { ToastContainer } from '@/components/ui/Toast'
-import { Dashboard } from '@/pages/Dashboard'
-import { Bookmarks } from '@/pages/Bookmarks'
-import { Tasks } from '@/pages/Tasks'
-import { Files } from '@/pages/Files'
-import { Notes } from '@/pages/Notes'
-import Chat from '@/pages/Chat'
-import { Settings } from '@/pages/Settings'
-import { Login } from '@/pages/Login'
-import { Youtube } from '@/pages/Youtube'
-import { Members } from '@/pages/Members'
-import { RemovedStuff } from '@/pages/RemovedStuff'
-import { AdminSettings } from '@/pages/AdminSettings'
-import { ColorSwitcher } from '@/pages/ColorSwitcher'
-import { AdminDashboard } from '@/pages/AdminDashboard'
-import { Stats } from '@/pages/Stats'
-import { Profile } from '@/pages/Profile'
-import { LearningPaths } from '@/pages/LearningPaths'
-import { GitHub } from '@/pages/GitHub'
-import { TimeTracking } from '@/pages/TimeTracking'
-import { Calendar } from '@/pages/Calendar'
-import { AuthCallback } from '@/pages/AuthCallback'
+import { Dashboard } from '@/pages/misc/Dashboard'
+import { Bookmarks } from '@/pages/content/Bookmarks'
+import { Tasks } from '@/pages/productivity/Tasks'
+import { Files } from '@/pages/content/Files'
+import { Notes } from '@/pages/content/Notes'
+import Chat from '@/pages/communication/Chat'
+import { Settings } from '@/pages/settings/Settings'
+import { Login } from '@/pages/auth/Login'
+import { Youtube } from '@/pages/content/Youtube'
+import { Members } from '@/pages/admin/Members'
+import { RemovedStuff } from '@/pages/misc/RemovedStuff'
+import { AdminSettings } from '@/pages/admin/AdminSettings'
+import { ColorSwitcher } from '@/pages/settings/ColorSwitcher'
+import { AdminDashboard } from '@/pages/admin/AdminDashboard'
+import { Stats } from '@/pages/productivity/Stats'
+import { Profile } from '@/pages/auth/Profile'
+import { LearningPaths } from '@/pages/content/LearningPaths'
+import { GitHub } from '@/pages/content/GitHub'
+import { TimeTracking } from '@/pages/productivity/TimeTracking'
+import { Calendar } from '@/pages/productivity/Calendar'
+import { AuthCallback } from '@/pages/auth/AuthCallback'
 import { AuthProvider, useAuth } from '@/lib/auth'
-import { Search } from '@/pages/Search'
-import { Analytics } from '@/pages/Analytics'
-import { Messages } from '@/pages/Messages'
-import { ShareTarget } from '@/pages/ShareTarget'
-import BrowserExtensionSettings from '@/pages/BrowserExtensionSettings'
+import { Search } from '@/pages/content/Search'
+import { Analytics } from '@/pages/admin/Analytics'
+import { Messages } from '@/pages/communication/Messages'
+import { ShareTarget } from '@/pages/misc/ShareTarget'
+import BrowserExtensionSettings from '@/pages/settings/BrowserExtensionSettings'
 import { initializeDemoMode, clearDemoMode, isEnvDemoMode } from '@/lib/demo-mode'
 import { onMount, createEffect } from 'solid-js'
 import { useNavigate } from '@solidjs/router'