feat(learn): the classifier program and its response cache (decision-engine 6.4)

learn/program.py: the declared signature (code, signals, roles, family in;
verdict, family, confidence, rationale with cited lines out), the
baseline instruction, rendering as [system: instruction + demonstrations]
-- byte-identical for every candidate, so the provider's prefix cache can
hit -- then [user: retrieved examples with their labels, the candidate
without one]. Signals pass validate_x first (no EXCLUDED_FIELDS, missing
instruments in words). Answers are one JSON object; one that does not
parse or cites no line inside the excerpt is asked once more at
temperature 0 and otherwise becomes unsure/parse_failed, never
not_vulnerable. Classify(k): sample 1 at 0.0, the rest at 0.7; score s =
mean p_j; majority verdict, ties unsure; a majority unsure cannot BLOCK.
Caller caches each response as responses/<sha>.json keyed by (model,
Model parameters digest, messages, temperature, sample, json_object) and
replays at $0; spend is priced from the recorded usage once per distinct
request, so a replay reports the same usd. Program.decide asserts the
evaluation boundary on the rendered ids before any call.

MeteredClient.complete passes temperature/logprobs through (only when
set); DeepSeekChatClient sends temperature beside thinking=disabled.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo

src/openultrasast/plane/budget.py

@@ -121,11 +121,20 @@ class MeteredClient:
         tools: list[dict[str, object]],
         timeout_seconds: int = 60,
         json_object: bool = False,
+        temperature: float | None = None,
+        logprobs: bool = False,
     ) -> ChatResponse:
+        """One metered call. ``temperature`` and ``logprobs`` pass through only when set, so a wrapped client that
+        does not take them (a scripted one) is called as before."""
         self.check()
+        extra: dict[str, Any] = {}
+        if temperature is not None:
+            extra["temperature"] = temperature
+        if logprobs:
+            extra["logprobs"] = True
         try:
             response = self.inner.complete(
-                model=model, messages=messages, tools=tools, timeout_seconds=timeout_seconds, json_object=json_object
+                model=model, messages=messages, tools=tools, timeout_seconds=timeout_seconds, json_object=json_object, **extra
             )
         except Exception as exc:
             self._absorb_rows()