Refactor import paths in app.py to remove 'app.' prefix

app.py

@@ -5,12 +5,12 @@ import time
 import gradio as gr
 import schedule
 
-from app.models.initializer import initialize_models, initialize_prefixes
-from app.runtime.scheduler import (cleanup_expired_sessions,
+from models.initializer import initialize_models, initialize_prefixes
+from runtime.scheduler import (cleanup_expired_sessions,
                                    push_and_clear_interactions,
                                    reset_counters_per_day,
                                    upload_and_rotate_logs)
-from app.ui.ui import render_ui
+from ui.ui import render_ui
 
 
 def run_scheduled_tasks():