Add Checkpoints feature with routes, template, and JavaScript integration

- Introduced CheckpointsRoutes for managing checkpoints-related endpoints and handling the checkpoints page.
- Added checkpoints.html template for rendering the checkpoints interface with a work-in-progress message.
- Implemented checkpoints.js to manage the initialization of the Checkpoints page and its components.
- Updated LoraManager to include checkpoints routes in the application setup, enhancing overall functionality.

py/routes/checkpoints_routes.py

@@ -0,0 +1,44 @@
+import os
+from aiohttp import web
+import jinja2
+import logging
+from ..config import config
+from ..services.settings_manager import settings
+
+logger = logging.getLogger(__name__)
+logging.getLogger('asyncio').setLevel(logging.CRITICAL)
+
+class CheckpointsRoutes:
+    """Route handlers for Checkpoints management endpoints"""
+    
+    def __init__(self):
+        self.template_env = jinja2.Environment(
+            loader=jinja2.FileSystemLoader(config.templates_path),
+            autoescape=True
+        )
+
+    async def handle_checkpoints_page(self, request: web.Request) -> web.Response:
+        """Handle GET /checkpoints request"""
+        try:
+            template = self.template_env.get_template('checkpoints.html')
+            rendered = template.render(
+                is_initializing=False,
+                settings=settings,
+                request=request
+            )
+            
+            return web.Response(
+                text=rendered,
+                content_type='text/html'
+            )
+            
+        except Exception as e:
+            logger.error(f"Error handling checkpoints request: {e}", exc_info=True)
+            return web.Response(
+                text="Error loading checkpoints page",
+                status=500
+            )
+
+    def setup_routes(self, app: web.Application):
+        """Register routes with the application"""
+        app.router.add_get('/checkpoints', self.handle_checkpoints_page)