feat: anti-hallucination params + retranscribe script for fixing broken transcripts

- transcribe.py: add --max-context 0, --entropy-thold 2.4, --max-len 60,
  --suppress-nst, --no-fallback to whisper.cpp to prevent hallucination loops
- transcribe.py: remove interactive quality gate (runs unattended now)
- run.bat: remove pause prompts for unattended operation
- retranscribe_tail.py: new script that detects hallucination bursts in SRT
  files, extracts and re-transcribes only the affected audio segments, then
  splices the result back together. Drops segments that re-hallucinate
  (silence/music). Backs up originals to transcripts/backup/.
- fix_hallucinations.bat: Windows wrapper for retranscribe_tail.py

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

transcribe.py

@@ -131,6 +131,11 @@ def transcribe_file(audio_path: str, output_base: str) -> bool:
         "--threads", str(os.cpu_count() or 4),
         "--beam-size", "1",
         "--best-of", "1",
+        "--max-context", "0",     # don't carry context between segments (prevents hallucination loops)
+        "--entropy-thold", "2.4", # reject high-entropy (hallucinated) segments
+        "--max-len", "60",        # shorter segments reduce drift
+        "--suppress-nst",         # suppress non-speech tokens (reduces hallucination on silence)
+        "--no-fallback",          # don't retry with higher temperature
         "--output-txt",
         "--output-srt",
         "--output-file", output_base,
@@ -260,17 +265,9 @@ def main():
             # Save manifest after each file (checkpoint)
             save_manifest(manifest)
 
-        # Quality gate: pause after first module
+        # Log milestone after first module (no longer pauses)
         if mod == manifest["modules"][0] and transcribed > 0:
-            log.info("\n" + "!" * 60)
-            log.info("QUALITY GATE: First module complete.")
-            log.info("Spot-check 2-3 transcripts in transcripts/ before continuing.")
-            log.info("Press Enter to continue, or Ctrl+C to abort...")
-            log.info("!" * 60)
-            try:
-                input()
-            except EOFError:
-                pass  # Non-interactive mode, continue
+            log.info(f"First module complete ({transcribed} files). Continuing automatically...")
 
     # Validation
     empty_outputs = [