The call record: every model call, for the operator's study (M6.6a)

nisse-core records each model call of every agent into a file beside its
state store (<state>.calls.db), for the status page (L7, X6):

- the request body exactly as sent (never headers), the raw response with
  its reasoning, the model asked and the one that answered, time, tokens
  and llama-server's own prompt reuse (timings.cache_n);
- its work item, role, run and purpose: Driver.run and nisse-dev's
  delegation loop open runs, nested; compaction, expert consults, the
  classifier and the go-ahead reader label their calls;
- provenance, worked out in BudgetedClient by comparing the events at
  each stage: each event sent with its log id and content as sent, which
  a compaction replaced, which fitting shortened (by how much) and
  dropped.

Content is stored once by hash, compressed. It is diagnostic only: the
agent never reads it, a failed write is logged once and recording stops
while the call goes on, and the file is deleted when the agent starts,
so its layout never migrates; CallReader refuses a layout it doesn't
know. While recording, the system prompt ends with one sentence saying
so. `call_record: false` in either agent's YAML turns it off.

The benchmark records each run beside that run's own state store, and
`--keep-runs DIR` keeps both for the page.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

nisse-dev/tests/test_bench.py

@@ -429,3 +429,26 @@ def test_runs_from_before_the_driver_read_as_its_defaults() -> None:
     old["tuning"]["executor"] = old["tuning"].pop("driver")
     [row] = summarise([old], current)
     assert row.tuning == ""
+
+
+def test_a_kept_run_leaves_its_state_and_call_record(tmp_path: Path) -> None:
+    # As the agent records itself (L7), so the status page can open a
+    # benchmark run (X6); each run gets its own record, and the client is
+    # left as it was.
+    from nisse_core.models.calls import CallReader
+
+    [task] = load_tasks(["write-function"])
+    client = Scripted(list(SOLVE_SLUGIFY))
+    record = run_task(task, FACTS, client, Tuning(), host=HOST, keep=tmp_path / "runs")
+
+    [kept] = list((tmp_path / "runs").iterdir())
+    assert kept.name.startswith("write-function-")
+    assert (kept / "state.db").exists()
+    [run] = CallReader(kept / "state.calls.db").runs()
+    assert (run["work_item"], run["role"], run["outcome"]) == (
+        "bench",
+        "driver",
+        "wait",
+    )
+    assert record.success
+    assert not hasattr(client, "call_recorder")