Refactor services and update documentation

- Refactor ban_service.py with improved error handling
- Refactor blocklist_service.py for better code organization
- Update geo_cache.py with performance improvements
- Update backend development guide and task documentation
- Update runner.csx script

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Docs/runner.csx

@@ -48,7 +48,7 @@ async Task<string> RunCopilot(IEnumerable<string> extraArgs, string prompt)
 {
     var output = new StringBuilder();
 
-    var argList = new List<string> { "--model", "claude-haiku-4.5", "--allow-all-tools" };
+    var argList = new List<string> { "--model", "auto", "--allow-all-tools" };
     argList.AddRange(extraArgs);
     argList.Add("-p");
     argList.Add(prompt);