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/semantic/__init__.py

@@ -0,0 +1,25 @@
+"""Propose/adjudicate/prove overlay: regex proposes, semantics adjudicates."""
+
+from .engines import joern_available, tree_sitter_available
+from .facts import FactLoadError, SemanticFacts, load_facts
+from .mechanisms import Mechanism, MechanismStore, append_mechanism, order_promotions
+from .overlay import OverlayError, OverlayRecord, adjudicate, finding_from_coverage, write_overlay
+from .prove_filter import filter_promoted_hotspots
+
+__all__ = [
+    "FactLoadError",
+    "Mechanism",
+    "MechanismStore",
+    "OverlayError",
+    "OverlayRecord",
+    "SemanticFacts",
+    "adjudicate",
+    "append_mechanism",
+    "filter_promoted_hotspots",
+    "finding_from_coverage",
+    "joern_available",
+    "load_facts",
+    "order_promotions",
+    "tree_sitter_available",
+    "write_overlay",
+]