Refactor static serving: use Blueprint static_folder, inline header

- Disable Flask default /static/ folder (static_folder=None in app.py)
- Add headerRoute blueprint to serve views/header/ at /assets/header/
- Configure transcription and scraper blueprints with static_folder
  pointing to their respective views/ subfolders
- Inline header HTML directly in headerLoader.js (remove fetch call)
- Update all HTML templates to use new /assets/... URLs

app.py

@@ -3,10 +3,12 @@ from flask import Flask
 from config import Config
 from routes.transcriptionRoute import transcription_bp
 from routes.scraperZLibraryRoute import scraperZLibraryRoute
+from routes.headerRoute import header_bp
 
 def create_app():
     """Application factory function"""
-    app = Flask(__name__, template_folder='views')
+    # static_folder=None → tắt hoàn toàn thư mục /static mặc định của Flask
+    app = Flask(__name__, template_folder='views', static_folder=None)
     
     # Load configuration
     app.config.from_object(Config)
@@ -18,6 +20,7 @@ def create_app():
     Config.init_app()
     
     # Register blueprints
+    app.register_blueprint(header_bp)
     app.register_blueprint(transcription_bp)
     app.register_blueprint(scraperZLibraryRoute, url_prefix='/scraperZLibrary')