Fix stale log tags and add ProcessingGeneration guard (INV-3)

- Diagnostic filter: [RESUME-ABORT -> [RESUME-ACTIVE] + [RESUME-CHECK]
  (without this, RESUME-ACTIVE entries wouldn't appear in event-diagnostics.log)
- Utilities.cs: [RESUME-ABORT] -> [RESUME-CHECK] in HasInterruptedToolExecution
- RESUME-ACTIVE InvokeOnUI: add ProcessingGeneration capture/check per INV-3/INV-12
  to prevent stale callback from re-arming IsProcessing after a user-initiated
  turn has already completed (race window: send -> complete -> stale callback)

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

Author: PureWeen

PolyPilot/Services/CopilotService.Persistence.cs

@@ -414,8 +414,12 @@ private async Task EnsureSessionConnectedAsync(string sessionName, SessionState
             {
                 Debug($"[RESUME-ACTIVE] '{sessionName}' has unmatched tool starts — marking as processing and waiting for events");
                 // INV-2: marshal to UI thread — EnsureSessionConnectedAsync runs from Task.Run.
+                // INV-3/INV-12: capture generation to prevent stale callback from re-arming
+                // IsProcessing after a user-initiated turn has already completed.
+                var gen = Interlocked.Read(ref state.ProcessingGeneration);
                 InvokeOnUI(() =>
                 {
+                    if (Interlocked.Read(ref state.ProcessingGeneration) != gen) return;
                     state.Info.IsProcessing = true;
                     state.Info.IsResumed = true;
                     state.HasUsedToolsThisTurn = true;

PolyPilot/Services/CopilotService.Utilities.cs

@@ -271,14 +271,14 @@ internal bool HasInterruptedToolExecution(string sessionId, string basePath)
             var result = unmatchedStarts > 0 && (sawShutdown || !sawOnlyControlEvents);
             if (result)
             {
-                Debug($"[RESUME-ABORT] events.jsonl for '{sessionId}' has {unmatchedStarts} interrupted tool(s) " +
+                Debug($"[RESUME-CHECK] events.jsonl for '{sessionId}' has {unmatchedStarts} interrupted tool(s) " +
                       $"(shutdown={sawShutdown}, force-kill={!sawShutdown})");
             }
             return result;
         }
         catch (Exception ex)
         {
-            Debug($"[RESUME-ABORT] Failed to check events.jsonl for '{sessionId}': {ex.Message}");
+            Debug($"[RESUME-CHECK] Failed to check events.jsonl for '{sessionId}': {ex.Message}");
             return false;
         }
     }

PolyPilot/Services/CopilotService.cs

@@ -694,7 +694,7 @@ internal static bool ShouldPersistDiagnostic(string message)
             message.StartsWith("[RECONNECT") || message.StartsWith("[UI-ERR") ||
             message.StartsWith("[DISPATCH") || message.StartsWith("[WATCHDOG") ||
             message.StartsWith("[HEALTH") || message.StartsWith("[ZERO-IDLE") ||
-            message.StartsWith("[PERMISSION") || message.StartsWith("[RESUME-ABORT") ||
+            message.StartsWith("[PERMISSION") || message.StartsWith("[RESUME-ACTIVE") || message.StartsWith("[RESUME-CHECK") ||
             message.StartsWith("[KEEPALIVE") || message.StartsWith("[ERROR") ||
             message.StartsWith("[ABORT") || message.StartsWith("[BRIDGE") ||
             message.StartsWith("[SYNC") ||