refactor: Extract models, config, and main app setup

- Create modular directory structure
  - Extract Pydantic models to api/models.py
  - Move configuration to config/settings.py
  - Create clean main.py with FastAPI app setup

  WIP: Routes and processor classes still need extraction

main.py

@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+"""
+NFOGuard - Main application entry point
+Automated NFO file management for Radarr and Sonarr
+"""
+import os
+import signal
+import sys
+import uvicorn
+from datetime import datetime, timezone
+from fastapi import FastAPI
+
+# Import configuration first
+from config.settings import config
+
+# Import other components
+from core.database import NFOGuardDatabase
+from core.nfo_manager import NFOManager
+from core.path_mapper import PathMapper
+from processors.tv_processor import TVProcessor
+from processors.movie_processor import MovieProcessor
+from webhooks.webhook_batcher import WebhookBatcher
+
+
+# ---------------------------
+# Version and Build Info
+# ---------------------------
+def get_version() -> str:
+    """Get version from VERSION file with build information"""
+    try:
+        with open("VERSION", "r", encoding="utf-8") as f:
+            version = f.read().strip()
+    except FileNotFoundError:
+        version = "development"
+    
+    # Add build source suffix for identification
+    build_source = os.environ.get("BUILD_SOURCE", "")
+    if build_source == "gitea":
+        if "gitea" not in version:  # Don't double-add gitea suffix
+            version = f"{version}-gitea"
+    
+    return version
+
+
+# ---------------------------
+# Application Setup
+# ---------------------------
+version = get_version()
+
+app = FastAPI(
+    title="NFOGuard",
+    description="Webhook server for preserving media import dates",
+    version=version
+)
+
+start_time = datetime.now(timezone.utc)
+
+# Initialize components
+db = NFOGuardDatabase(config.db_path)
+nfo_manager = NFOManager(config.manager_brand, config.debug)
+path_mapper = PathMapper(config)
+tv_processor = TVProcessor(db, nfo_manager, path_mapper)
+movie_processor = MovieProcessor(db, nfo_manager, path_mapper)
+batcher = WebhookBatcher(nfo_manager)
+
+# Import and register routes
+from api.routes import register_routes
+register_routes(app, tv_processor, movie_processor, batcher, db, start_time, version)
+
+
+# ---------------------------
+# Signal Handlers
+# ---------------------------
+def signal_handler(signum, frame):
+    """Handle shutdown signals gracefully"""
+    print(f"Received signal {signum}, shutting down gracefully...")
+    sys.exit(0)
+
+
+# ---------------------------
+# Main Entry Point
+# ---------------------------
+if __name__ == "__main__":
+    # Register signal handlers for graceful shutdown
+    signal.signal(signal.SIGTERM, signal_handler)
+    signal.signal(signal.SIGINT, signal_handler)
+    
+    print("Starting NFOGuard")
+    print(f"Version: {version}")
+    print(f"TV paths: {[str(p) for p in config.tv_paths]}")
+    print(f"Movie paths: {[str(p) for p in config.movie_paths]}")
+    print(f"Database: {config.db_path}")
+    print(f"Config: manage_nfo={config.manage_nfo}, fix_mtimes={config.fix_dir_mtimes}")
+    print(f"Movie priority: {config.movie_priority}")
+    
+    try:
+        uvicorn.run(
+            app,
+            host="0.0.0.0", 
+            port=int(os.environ.get("PORT", "8080")),
+            reload=False
+        )
+    except KeyboardInterrupt:
+        print("NFOGuard stopped by user")
+    except Exception as e:
+        print(f"NFOGuard crashed: {e}")
+        sys.exit(1)