feat(propose-adjudicate-prove): overlay adjudicates inventory before prove

Regex inventory stays the proposer. MAP attaches promote/demote/unadjudicated/coverage
from intra-file taint (tree-sitter when a grammar parses, Python ast as last resort).
Deep sandboxes promotions only, ordered by the existing heuristic ranker plus optional
OpenRouter mechanism recall. The SAST pair slice scores overlay outcomes; the stage-1
detection gate and local pair gate stay inventory-only.

src/openultrasast/improve/__init__.py

@@ -1,5 +1,6 @@
 """Bounded, gated self-improvement loop over the ruleset/policy governance data."""
 
+from ..pairs import build_pair_signals
 from .evolve import RoundOutcome, build_rule_signals, propose_status_edits, run_improvement, run_round
 from .journal import load_journal, reverted_edit_keys
 from .validator import (
@@ -20,6 +21,7 @@ __all__ = [
     "RuleStatusEdit",
     "StrictValidationError",
     "VALID_LEVERS",
+    "build_pair_signals",
     "build_rule_signals",
     "edits_to_ledger",
     "load_journal",