feat(decision): make the accept lines tunable from the environment

`LOCAL_ACCEPT` and `TEXT_MIN_SHARED` were module constants, so sweeping
them meant editing the source and restarting. Both lanes now read
`DORAYAKI_LOCAL_ACCEPT` / `DORAYAKI_TEXT_MIN_SHARED` with the constants
as defaults, which is what the calibration sweeps need and what a demo
host needs to loosen or tighten the gates without a code change.

Defaults are unchanged, so the shipped behaviour is identical.

recognization/code/engine.py

@@ -507,7 +507,7 @@ class RecognitionEngine:
         know about. Without OCR the local lane stands alone.
         """
         from identity import decide_identity
-        from identity_lanes import DecisionPolicy
+        from identity_lanes import LOCAL_ACCEPT, TEXT_MIN_SHARED, DecisionPolicy
 
         if self.identity_scale != "local":
             return decide_identity(
@@ -525,9 +525,12 @@ class RecognitionEngine:
             text_rank = sorted(
                 text_lane.scores_from_text(read).items(), key=lambda kv: kv[1], reverse=True
             )
-        return DecisionPolicy(signatures=text_lane.signatures if text_lane else None).decide(
-            lane.rank(crop), text_rank, text_read=read
+        policy = DecisionPolicy(
+            local_accept=float(os.environ.get("DORAYAKI_LOCAL_ACCEPT", LOCAL_ACCEPT)),
+            text_min_shared=int(os.environ.get("DORAYAKI_TEXT_MIN_SHARED", TEXT_MIN_SHARED)),
+            signatures=text_lane.signatures if text_lane else None,
         )
+        return policy.decide(lane.rank(crop), text_rank, text_read=read)
 
     def score_crop_lanes(
         self, crop: Any, method: Optional[str] = None, skip_ocr: bool = False

recognization/code/live.py

@@ -1280,7 +1280,7 @@ class LiveSession:
 
 
             from identity import aggregate_votes, decide_identity
-            from identity_lanes import DecisionPolicy
+            from identity_lanes import LOCAL_ACCEPT, TEXT_MIN_SHARED, DecisionPolicy
 
             mean_scores = aggregate_votes(track.observations)
             scale = getattr(self.engine, "identity_scale", "inlier")
@@ -1309,7 +1309,9 @@ class LiveSession:
                 # in an empty observation halves a good confidence below the
                 # accept line, which is the dilution the cosine branch guards too.
                 decision = DecisionPolicy(
-                    signatures=text_lane.signatures if text_lane else None
+                    local_accept=float(os.environ.get("DORAYAKI_LOCAL_ACCEPT", LOCAL_ACCEPT)),
+                    text_min_shared=int(os.environ.get("DORAYAKI_TEXT_MIN_SHARED", TEXT_MIN_SHARED)),
+                    signatures=text_lane.signatures if text_lane else None,
                 ).decide(list(scores.items()), text_rank, text_read=text_read)
             elif scale == "van":
                 # Van's contract on the stream: the aggregate's top SKU, always