fix(window): let an activate cancel the restore's own resize

The traces settled it: on a restore FMX fires its resize BEFORE the activate,
already reporting "not maximised" — so any snapshot taken at activate time was
too late. A genuine user resize, by contrast, is never followed by an activate
(the window is already active).

That is the discriminator. A resize no longer commits immediately: it queues,
and an activate arriving first cancels it, leaving the intent intact for the
correction to re-apply. Verified against every sequence in the log, including
the startup burst (three resizes then an activate), which must NOT be mistaken
for the user un-maximising.

Skips resizes that don't change the maximised state, so dragging the window
edge no longer floods the queue or the log.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

delphi-backend/UMainForm.pas

@@ -85,6 +85,8 @@ type
     // Set from activate until the queued correction runs, so the restore's
     // own resize is not mistaken for the user resizing the window.
     FRestoring: Boolean;
+    // A resize awaiting confirmation that no activate follows it.
+    FResizePending, FPendingZoomed: Boolean;
     FServer: TPMHTTPServer;
     FBridge: TPMBridge;
     // Accumulates base64 chunks for large file saves (attachments too big
@@ -182,6 +184,7 @@ begin
   FWantMaximized := (WindowState = TWindowState.wsMaximized);
   FWasMinimized  := False;
   FRestoring     := False;
+  FResizePending := False;
   OnResize   := FormResizeTrackState;
   OnActivate := FormActivateRestoreState;
 
@@ -1530,15 +1533,27 @@ begin
     LogLine('[winstate] resize: minimised');
     Exit;
   end;
-  if FRestoring then
-  begin
-    // The restore's own resize: reports whatever FMX decided, not intent.
-    LogLine('[winstate] resize during restore ignored (zoomed=' +
-      BoolToStr(IsZoomed(LHwnd), True) + ')');
-    Exit;
-  end;
-  FWantMaximized := IsZoomed(LHwnd);  // genuine user-driven resize
-  LogLine('[winstate] resize: want_max=' + BoolToStr(FWantMaximized, True));
+  // Observed order on a restore: FMX fires its resize BEFORE the activate, so
+  // committing here would destroy the intent we are about to need. A genuine
+  // user resize is never followed by an activate (the window is already
+  // active) — so defer the commit one message-pump turn and let an incoming
+  // activate cancel it.
+  // Nothing to learn when the maximised state is unchanged — and this is what
+  // keeps a mouse-drag resize (which fires continuously) from flooding the
+  // queue and the log.
+  if IsZoomed(LHwnd) = FWantMaximized then Exit;
+  FPendingZoomed  := IsZoomed(LHwnd);
+  FResizePending  := True;
+  LogLine('[winstate] resize pending: zoomed=' + BoolToStr(FPendingZoomed, True));
+  TThread.ForceQueue(nil,
+    procedure
+    begin
+      if not FResizePending then Exit;   // an activate claimed it: a restore
+      FResizePending := False;
+      FWantMaximized := FPendingZoomed;
+      LogLine('[winstate] resize committed: want_max=' +
+              BoolToStr(FWantMaximized, True));
+    end);
 end;
 
 // Re-apply the remembered state once the window is back. Runs however the
@@ -1553,6 +1568,9 @@ begin
   // Snapshot the intent NOW: FMX's restore-time resize may land before or
   // after this activate depending on how the window came back, and if it
   // lands first it would already have overwritten FWantMaximized.
+  // Cancel a resize that has not committed yet: an activate right after one
+  // means this was a restore, not the user resizing the window.
+  FResizePending := False;
   LWant := FWantMaximized;
   if FRestoring then Exit;            // one correction per return
   FRestoring := True;