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/model/audit.py

@@ -73,9 +73,9 @@ SPEC_OWNED = {
         "learned-decision-engine Req 8.1: model role classification per file chunk (model_sinks.py moved in); "
         "its Run template comes with the harvest (task 5)"
     ),
-    "learn.retrieve": (
-        "learned-decision-engine Req 3.2/3.4: retrieval from the local memory and the evaluation boundary; "
-        "the program (task 6.4) and `ousast learn compile` (6.5) are its callers"
+    "learn.program": (
+        "learned-decision-engine Req 3.1/3.3: the AI classifier program (signature, Retrieve -> Classify(k), response "
+        "cache); `ousast learn compile` (task 6.5) and the decide task (task 8) are its callers"
     ),
     "plane.workspaces": "ai-service-plane task 4: Workspace manifests per case pin of a population; `ousast plane workspaces`",
     "plane.runner": "ai-service-plane Req 4.1-4.4: the ax-task-runner entrypoint (PID 1 of the task image); delivers the output directory",