fix: player connectivity and media download pipeline

- nginx: add /api/ shortcut block (no portal auth, X-Script-Name /digiserver,
  Host $http_host) so players can reach DigiServer API without /digiserver prefix
- nginx: use $http_host in /api/ block so Flask host_url includes port — fixes
  media download URLs missing :8080 (was http://ip/digiserver/... not http://ip:8080/...)
- player main.py: fix double-port bug when server_ip already contains a port
  (e.g. 192.168.0.230:8080 was producing http://192.168.0.230:8080:80)
- get_playlists_v2.py: force re-sync when server version differs OR local media
  files are missing on disk — fixes stale playlist after server reset
- digiserver api.py: playlist endpoint builds full media URLs using script_root
  from X-Script-Name header set by nginx
- weblink support, player build/deploy improvements, manage-playlist AJAX prefix fix

digiserver-v2/migrations/add_weblink_url_to_content.py

@@ -0,0 +1,34 @@
+"""Add url column to content table for web link playlist items.
+
+Web link items are stored as Content rows with content_type='weblink' and the
+target web page URL in the new 'url' column (NULL for file-based content).
+
+Run with:  python migrations/add_weblink_url_to_content.py
+"""
+import sys
+sys.path.insert(0, '/app')
+
+from app.app import create_app
+from app.extensions import db
+from sqlalchemy import text
+
+app = create_app()
+
+with app.app_context():
+    print("Adding url column to content table...")
+
+    try:
+        inspector = db.inspect(db.engine)
+        columns = [col['name'] for col in inspector.get_columns('content')]
+
+        if 'url' not in columns:
+            with db.engine.connect() as conn:
+                conn.execute(text('ALTER TABLE content ADD COLUMN url VARCHAR(2048)'))
+                conn.commit()
+            print("\u2713 url column added to content table!")
+        else:
+            print("\u2713 url column already exists in content table.")
+
+    except Exception as e:
+        print(f"Error adding url column: {str(e)}")
+        sys.exit(1)