fix(ui): suppress [TikTok] and [Apify] log lines in non-TTY mode

Only print debug log lines when running in an interactive terminal.
In Claude Code (non-TTY), the spinner system handles progress display,
so these raw log lines just add noise.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/lib/tiktok.py

@@ -128,9 +128,10 @@ def _extract_core_subject(topic: str) -> str:
 
 
 def _log(msg: str):
-    """Log to stderr."""
-    sys.stderr.write(f"[TikTok] {msg}\n")
-    sys.stderr.flush()
+    """Log to stderr (only in interactive terminals; spinner handles non-TTY)."""
+    if sys.stderr.isatty():
+        sys.stderr.write(f"[TikTok] {msg}\n")
+        sys.stderr.flush()
 
 
 def _parse_date(item: Dict[str, Any]) -> Optional[str]: