feat(matching): implement two-stage matching with DeepSeek arbiter, fail-stop guard, and zero-probability filter

bot/tools/test_matching.py

@@ -81,6 +81,25 @@ async def mock_tests() -> None:
                 for m in ms for v in m.get("variants", [])}
     matching.match_with_deepseek = mock_fallback_below_floor
 
+    orig_arbiter = matching.adjudicate_with_deepseek
+    async def mock_arbiter(*args, **kwargs):
+        items = kwargs.get("items") or (args[2] if len(args) > 2 else [])
+        res = {}
+        for it in items:
+            choice = it.get("jev_choice")
+            conf = it.get("jev_confidence", 0.0)
+            if choice == "منشانه" and conf >= 0.8:
+                entry = {"status": "exact", "id": "p2", "name": "منشانه", "field": it["field"], "variants": it["variants"]}
+            elif choice == "دفتر" and conf >= 0.6:
+                entry = {"status": "ambiguity", "id": "p1", "name": "دفتر", "field": it["field"], "variants": it["variants"],
+                         "candidates": [{"id": "p1", "name": "دفتر", "prob": conf}]}
+            else:
+                entry = {"status": "new", "id": None, "name": None, "field": it["field"], "variants": it["variants"], "candidates": []}
+            for v in it["variants"]:
+                res[normalize_text(v)] = entry
+        return res
+    matching.adjudicate_with_deepseek = mock_arbiter
+
     mentions = [
         {"field": "project", "variants": ["منشیانه"]},
         {"field": "project", "variants": ["دفتر", "دفر"]},
@@ -91,6 +110,7 @@ async def mock_tests() -> None:
         res = await matching.resolve_mentions(ctx, {"items": []}, mentions, None)
     finally:
         matching.match_with_deepseek = orig_fallback
+        matching.adjudicate_with_deepseek = orig_arbiter
 
     r0 = matching.lookup(res, "منشیانه")
     r1 = matching.lookup(res, "دفر")          # variant key resolves too