pairs: default to hand-authored pairs_authored.json; drop contaminated prog_wider/widest

Progressive (prog_wide_clean) and authored deploy within noise (0.042 vs 0.050
hack, both 0.143 solve); default to authored as the canonical no-cheat label
source. prog_wider/widest held genuine contamination, superseded by curated
prog_wide_clean (kept for the progressive-vs-authored comparison).

Co-Authored-By: Claudypoo <288921227+claudypoo@users.noreply.github.com>

src/vgrout/train_config.py

@@ -42,7 +42,7 @@ class Config:
     v_hack_tau_axis: float = 0.0
     v_hack_drop_bottom_frac: float = 0.25
     vhack_refresh_every: int = 5
-    vhack_pairs_path: Path = Path("out/pairsets/prog_wide_clean.json")
+    vhack_pairs_path: Path = Path("out/pairsets/pairs_authored.json")
 
     routeV_random_v_seed: int | None = None
     # >1: route by the oriented top-k SVD subspace (gate = max_i cos(g, v_i)) instead of the