Cleanup: move transcripts out, scripts into scripts/, drop scaffold

- transcripts/ moved to ~/shorashim-transcripts (separate from code repo)
  Added to .gitignore so it stays out
- src/l1_aron/build_l1.py → scripts/build_l1.py
- src/tools/conversation_search.py → scripts/conversation_search.py
- Removed empty src/ scaffolding (l0_luchot, sanhedrin, shema_layer,
  shoresh_engine, urim_v_tumim — all .gitkeep stubs from an earlier
  layout, never used; the real code lives in shoresh-engine/,
  sanhedrin/, vav_pipeline/, etc.)
- Removed Untitled/ and erl_crash.dump (untracked junk)

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

.gitignore

@@ -48,3 +48,4 @@ korban_processor/__pycache__/
 # Misc
 Untitled/
 aws-export/
+transcripts/