face_monochromatic_pairs: rename check_conj_3_8_scaled → check_conj_final_scaled; add n=21-24 test

Rename the shared helper module to a number-resistant name. Update
all 26 dependent scripts via sed.

Add experiments/test_n_21_to_24.py — extends the empirical check
beyond |V(G)| ≤ 20 to n_G ∈ [21, 24]. Checks per chord-apex+Kempe
colouring:
  (1) h_φ constant on V(K_b)? (counterexample to Corollary 5.4)
  (2) h_φ constant on V(K_b) ∪ V(K_c)? (counterexample to Conj 5.1)
  (3) Deciding face exists?

Writes results incrementally to test_n_21_to_24_results.jsonl (one
JSON line per triangulation, plus n-level and grand summaries).
Emits PROGRESS lines every 10 minutes (default) to stdout for live
monitoring.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

papers/face_monochromatic_pairs/experiments/check_shared_parity.py

@@ -24,7 +24,7 @@ from sage.graphs.graph_generators import graphs
 HERE = os.path.dirname(os.path.abspath(__file__))
 sys.path.insert(0, HERE)
 
-from check_conj_3_8_scaled import (
+from check_conj_final_scaled import (
     apply_reduction,
     proper_3_edge_colorings,
     matches_chord_apex_kempe,