Enhance FreebitOperationsService to improve entry cleanup and error handling

- Updated logic to prevent cleanup of entries with a cancellation, ensuring proper handling of account states.
- Enhanced error handling to fail fast on non-404 errors, optimizing resource usage during API requests.
- Improved comments for clarity on the cleanup process and error handling behavior.

apps/bff/src/integrations/freebit/services/freebit-operations.service.ts

@@ -82,7 +82,10 @@ export class FreebitOperationsService {
       );
 
       // If all timestamps are stale (or entry is empty), mark for removal
-      if (timestamps.length === 0 || timestamps.every(t => t < staleThreshold)) {
+      // EXCEPT: Never clean up entries with a cancellation - cancellation blocks plan changes permanently
+      // until the account is actually cancelled or the cancellation is reverted externally
+      const hasCancellation = typeof entry.cancellation === "number";
+      if (!hasCancellation && (timestamps.length === 0 || timestamps.every(t => t < staleThreshold))) {
         accountsToRemove.push(account);
       }
     }
@@ -210,8 +213,11 @@ export class FreebitOperationsService {
         } catch (err: unknown) {
           lastError = err;
           if (getErrorMessage(err).includes("HTTP 404")) {
-            continue; // try next endpoint
+            continue; // try next endpoint for 404 (endpoint not found)
           }
+          // For non-404 errors (auth failures, rate limits, 500s, etc.), fail fast
+          // instead of wasting resources retrying fundamentally broken requests
+          break;
         }
       }