Write a App in python with Flask. Make sure that you do not override the existing main.py
Use existing classes but if a chnae is needed make sure main.py works as before. Look at Main.py to understand the function.
Write all files in folder src/server/
Use the checklist to write the app. start on the first task. make sure each task is finished.
mark a finished task with x, and save it.
Stop if all Task are finshed

AniWorld Web App Feature Checklist

[x] Anime Search
    [x] Implement search bar UI (auto-suggest, clear button)
    [x] Connect search to backend loader
    [x] Display search results (name, link, cover)
    [x] Add anime from search results to global list

[x] Global Series List
    [x] Display all series in a card/grid layout
    [x] Show missing episodes per series
    [x] Show cover, name, folder, and quick actions
    [x] Multi-select series with checkboxes
    [x] Select all series option

[x] Download Management
    [x] Start download for selected series
    [x] Show overall and per-episode progress bars
    [x] Status indicators (downloading, finished, error)
    [x] Pause, resume, cancel actions

[x] Reinit/Rescan Functionality
    [x] UI button for rescan/reinit
    [x] Show scanning progress modal
    [x] Live updates during scan
    [x] Update global series list after scan

[x] Status & Feedback
    [x] Real-time status updates for scanning/downloading
    [x] Snackbar/toast notifications for actions
    [x] Centralized error dialog (friendly messages)

[x] Configuration & Environment
    [x] Read base directory from environment variable
    [x] UI for changing directory (if needed)
    [x] Display current config (read-only)

[x] Security
    [x] Validate all user inputs
    [x] Do not expose internal errors or stack traces

[x] Modern GUI Concepts
    [x] Fluent UI design (Windows 11 iconography, shapes, typography)
    [x] Responsive design for desktop/mobile
    [x] Dark and light mode support
    [x] Localization-ready (resource files for text)
    [x] Effortless, calm, and familiar user experience

[] Authentication & Security
    [] Implement login page with master password authentication
    [] Add password configuration option in config file
    [] Add session management for authenticated users
    [] Implement fail2ban compatible logging for failed login attempts
    [] Use standard fail2ban log format: "authentication failure for [IP] user [attempt]"

[] Enhanced Anime Display
    [] Modify main anime list to show animes with missing episodes first
    [] Add filter toggle to show only animes with missing episodes
    [] Implement alphabetical sorting option for anime names
    [] Make only animes with missing episodes selectable for download
    [] Add visual indicators for animes with/without missing episodes

[] Download Queue Management
    [] Create dedicated download queue page showing active downloads
    [] Display current download progress with episode name and download speed
    [] Show download queue with pending items
    [] Implement download queue status indicators (queued, downloading, completed, failed)
    [] Add download queue statistics (total items, ETA, current speed)

[] Process Locking System
    [] Implement rescan process lock (only one rescan at a time)
    [] Add UI feedback when rescan is already running
    [] Disable rescan button when process is active
    [] Implement download queue lock (only one download process)
    [] Prevent duplicate episodes in download queue
    [] Add queue deduplication logic

[] Scheduled Operations
    [] Add configuration option for scheduled rescan time (HH:MM format)
    [] Implement daily automatic rescan at configured time
    [] Auto-start download of missing episodes after scheduled rescan
    [] Add UI to configure/view scheduled rescan settings
    [] Show next scheduled rescan time in UI

[] Enhanced Logging
    [] Configure console logging to show only essential information
    [] Remove progress bars from console output
    [] Implement structured logging for web interface
    [] Add authentication failure logging in fail2ban format
    [] Separate download progress logging from console output
    [] Add log level configuration (INFO, WARNING, ERROR)