Attempt to remove flickering

app.py

@@ -213,6 +213,15 @@ def process_search_tta(
             pngs.sort(key=lambda p: int(os.path.splitext(os.path.basename(p))[0]))
             for fp in pngs:
                 if fp not in sent_tta:
+                    # Ensure file is fully written (non-empty & readable)
+                    try:
+                        if os.path.getsize(fp) == 0:
+                            continue
+                        with open(fp, "rb") as fh:
+                            fh.read(1)
+                    except Exception:
+                        # Skip this round; we'll retry next poll
+                        continue
                     sent_tta.add(fp)
                     last_tta = fp
                     updated = True
@@ -221,6 +230,13 @@ def process_search_tta(
             pngs.sort(key=lambda p: int(os.path.splitext(os.path.basename(p))[0]))
             for fp in pngs:
                 if fp not in sent_no:
+                    try:
+                        if os.path.getsize(fp) == 0:
+                            continue
+                        with open(fp, "rb") as fh:
+                            fh.read(1)
+                    except Exception:
+                        continue
                     sent_no.add(fp)
                     last_no = fp
                     updated = True