fix: skip API calls when all keys are rate-limited in -collect mode

Pre-flight check on the CollectNotes loop now sleeps until at least one
key recovers instead of issuing a wasted 429-bound request per iteration.
Extracts the countdown into ApiKeyPool.SleepUntilAnyAvailable (30s refresh)
and reuses it in CollectLikes and GrabNotes.

Co-Authored-By: Claude Opus 4.7 <[email protected]>

URLNotesGrabberCORE/Program.cs

@@ -736,19 +736,7 @@ namespace URLNotesGrabberCORE
                             int retry = response.retryInSeconds > 0 ? response.retryInSeconds : 60;
                             ApiKeyPool.MarkRateLimited(key, retry);
 
-                            if (ApiKeyPool.IsAllRateLimited(out int minRetry))
-                            {
-                                Console.WriteLine($"[Pool] All keys rate-limited, waiting {minRetry}s before retry");
-                                int remaining = minRetry;
-                                DateTime retryAt = DateTime.Now.AddSeconds(minRetry);
-                                while (remaining > 0)
-                                {
-                                    Console.WriteLine("Sleeping for {0} more seconds, until {1}", remaining, retryAt.ToShortTimeString());
-                                    int sleepSeconds = Math.Min(60, remaining);
-                                    Thread.Sleep(sleepSeconds * 1000);
-                                    remaining -= sleepSeconds;
-                                }
-                            }
+                            ApiKeyPool.SleepUntilAnyAvailable(30);
                             continue;
                         }
 
@@ -969,19 +957,7 @@ namespace URLNotesGrabberCORE
                     int retry = response.retryInSeconds > 0 ? response.retryInSeconds : 60;
                     ApiKeyPool.MarkRateLimited(key, retry);
 
-                    if (ApiKeyPool.IsAllRateLimited(out int minRetry))
-                    {
-                        Console.WriteLine($"[Pool] All keys rate-limited, waiting {minRetry}s before returning");
-                        int remaining = minRetry;
-                        DateTime retryAt = DateTime.Now.AddSeconds(minRetry);
-                        while (remaining > 0)
-                        {
-                            Console.WriteLine("Sleeping for {0} more seconds, until {1}", remaining, retryAt.ToShortTimeString());
-                            int sleepSeconds = Math.Min(60, remaining);
-                            Thread.Sleep(sleepSeconds * 1000);
-                            remaining -= sleepSeconds;
-                        }
-                    }
+                    ApiKeyPool.SleepUntilAnyAvailable(30);
                     return response.statusCode;
                 }
 
@@ -1093,6 +1069,8 @@ namespace URLNotesGrabberCORE
                 {
                     while (posts.Count > 0)
                     {
+                        ApiKeyPool.SleepUntilAnyAvailable(30);
+
                         var post = posts[0]; // Process the first post in the list
                         string status;