fix(#3277): forward EGG_CONTEXT_MEASUREMENT into agent pods

docs/architecture/context-discipline.md

@@ -201,12 +201,15 @@ switches, each read in exactly one place:
 | `EGG_CONTEXT_MEASUREMENT` | `egg_agent.measurement.measurement_enabled` | Opt-in for the emit-only per-event measurement surfaces (#3249). ON (and `EGG_PIPELINE_ID` set) → after each BRC event the agent emits the six context-discipline metrics through the progress + heartbeat surfaces; OFF (default) → the legacy path is byte-identical (no measurement emit). |
 | `EGG_REAL_BACKEND_WINDOW` | `egg_agent.measurement._resolve_real_window` | Cross-boundary integer override of the model's real backend window, mirroring `EGG_RESEED_THRESHOLD`. Because `orchestrator` is off `PYTHONPATH` in-pod, this is the channel that populates the window-relative metrics (`real_backend_window` / `window_utilization`) in production; the orchestrator import is a dev/CI-only fallback, and both metrics degrade to `None` when neither yields a value. |
 
-**Setting the flags in production.** `EGG_CONTEXT_DISCIPLINE` and
-`EGG_SESSION_RESUME` are read in-pod but must be set on the **orchestrator
-deployment** — `orchestrator/kubernetes_spawner.py` forwards them from the
+**Setting the flags in production.** `EGG_CONTEXT_DISCIPLINE`,
+`EGG_CONTEXT_MEASUREMENT`, and `EGG_SESSION_RESUME` are read in-pod but must be
+set on the **orchestrator deployment** —
+`orchestrator/kubernetes_spawner.py` forwards them from the
 orchestrator's own environment into every spawned agent Job
 (`_FORWARDED_DISCIPLINE_ENV_KEYS`, added in
-[#3272](https://github.com/jwbron/egg/issues/3272)). Nothing else wires them
+[#3272](https://github.com/jwbron/egg/issues/3272); `EGG_CONTEXT_MEASUREMENT`
+added in [#3277](https://github.com/jwbron/egg/issues/3277) once #3271's in-pod
+consumer landed). Nothing else wires them
 into the Job env (`envFrom` is absent; `sandbox_env` is built from pipeline
 fields), so a `kubectl set env` on the pods directly has no effect. The
 forward runs before the per-spawn `extra_env` merge, so a targeted

orchestrator/kubernetes_spawner.py

@@ -221,15 +221,14 @@ def _resolve_wait_producer_allowlist(phase: str | None, role: str, repo: str | N
 # the per-spawn substrate (``EGG_SESSION_STATE_FILE`` / ``EGG_RESEED_THRESHOLD``)
 # needs real per-pod wiring and is deliberately NOT a blind forward.
 #
-# NOTE: the #3249 emit-only measurement knob (``EGG_CONTEXT_MEASUREMENT``) is
-# deliberately NOT forwarded yet — it has no in-pod consumer (no
-# ``egg_agent.measurement`` module exists), and the flag-name auto-discovery
-# convention (``sandbox/tests/test_context_discipline_flag.py``) means the
-# eventual consumer's flag name isn't pinned. Forwarding a guessed name now would
-# be a silent no-op. Add it here once #3249's emit consumer lands under a fixed
-# name.
+# ``EGG_CONTEXT_MEASUREMENT`` forwards the #3249 emit-only measurement knob: its
+# in-pod consumer landed in #3271 as ``egg_agent.measurement`` under the fixed
+# name ``MEASUREMENT_ENV = "EGG_CONTEXT_MEASUREMENT"``, which ``record_measurement``
+# gates on. Without forwarding it the surfaces no-op in every pod (#3277), so the
+# instrumented proving run captures zero metrics even with discipline active.
 _FORWARDED_DISCIPLINE_ENV_KEYS: tuple[str, ...] = (
     "EGG_CONTEXT_DISCIPLINE",
+    "EGG_CONTEXT_MEASUREMENT",
     "EGG_SESSION_RESUME",
 )
 

orchestrator/tests/test_kubernetes_spawner.py

@@ -975,6 +975,7 @@ def test_flags_forwarded_into_pod_env_when_set(
         self, spawner, mock_k8s_client, mock_gateway, monkeypatch
     ):
         monkeypatch.setenv("EGG_CONTEXT_DISCIPLINE", "true")
+        monkeypatch.setenv("EGG_CONTEXT_MEASUREMENT", "true")
         monkeypatch.setenv("EGG_SESSION_RESUME", "1")
         result = spawner.spawn_agent_job(
             pipeline_id="pipe-cd",
@@ -985,10 +986,14 @@ def test_flags_forwarded_into_pod_env_when_set(
         )
         env = result.environment
         assert env["EGG_CONTEXT_DISCIPLINE"] == "true"
+        # #3277: the measurement knob must ride along, else #3271's emit
+        # surfaces no-op in-pod and the proving run captures zero metrics.
+        assert env["EGG_CONTEXT_MEASUREMENT"] == "true"
         assert env["EGG_SESSION_RESUME"] == "1"
 
     def test_flags_absent_when_unset(self, spawner, mock_k8s_client, mock_gateway, monkeypatch):
         monkeypatch.delenv("EGG_CONTEXT_DISCIPLINE", raising=False)
+        monkeypatch.delenv("EGG_CONTEXT_MEASUREMENT", raising=False)
         monkeypatch.delenv("EGG_SESSION_RESUME", raising=False)
         result = spawner.spawn_agent_job(
             pipeline_id="pipe-cd2",
@@ -999,6 +1004,7 @@ def test_flags_absent_when_unset(self, spawner, mock_k8s_client, mock_gateway, m
         )
         env = result.environment
         assert "EGG_CONTEXT_DISCIPLINE" not in env
+        assert "EGG_CONTEXT_MEASUREMENT" not in env
         assert "EGG_SESSION_RESUME" not in env
 
     def test_extra_env_overrides_forwarded_flag(