SLM-253: close LOT2-02 not_authorized via downstream gate

docs/design/iter-slm253-lot2-02-not-authorized-20260725.json

@@ -0,0 +1,26 @@
+{
+  "contract_hash": "d312bc70e05cbff00233edb79e34408bb4a9e7e7c09dffd14c64497e73f61eaa",
+  "contract_id": "structured-latent-readout-gate-v1",
+  "issue": {
+    "activation_requirement": "SLM-251 (LOT1-02) provides a qualified faithful causal checkpoint/recipe and continued explicit control, and SLM-252 (LOT2-01) selects or bounds the supervision timing/readout routing.",
+    "alias": "LOT2-02",
+    "gate_contract_id": "structured-latent-readout-gate-v1",
+    "linear_issue": "SLM-253",
+    "slug": "lot2-02-structured-readout",
+    "title": "Compare independent-token PCL with structured, set-valued, and block-autoregressive semantic readouts"
+  },
+  "lot1_01_disposition": "not_authorized",
+  "lot1_02_disposition": "not_authorized",
+  "schema_version": "lot_downstream_gate/v1",
+  "verdict": "not_authorized",
+  "verdict_rationale": "LOT2-02 (SLM-253) activation requires: SLM-251 (LOT1-02) provides a qualified faithful causal checkpoint/recipe and continued explicit control, and SLM-252 (LOT2-01) selects or bounds the supervision timing/readout routing. The LOT1-02 launch gate reports 'not_authorized' (LOT1-01 disposition 'not_authorized'): no faithful K x c model path, curriculum, Stage 0 parent, or continued-explicit control exists, and SLM-249's oracle ceiling is not positive. Closing not_authorized in plan-only/bounded-diagnostic mode; no training, factorial, intervention, or systems code is added by this disposition.",
+  "version_stamp": {
+    "code_commit": "e77a0efc18618a854e95938357b97d09b62f9a38",
+    "code_dirty": true,
+    "components": {
+      "harness.experiments": "v112"
+    },
+    "stamp_schema": "version_stamp/v1",
+    "stamped_at": "2026-07-25T16:08:42.975048+00:00"
+  }
+}

docs/design/iter-slm253-lot2-02-not-authorized-20260725.md

@@ -0,0 +1,15 @@
+# SLM-253 LOT2-02 — Downstream-gate disposition (structured-latent-readout-gate-v1)
+
+Verdict: **not_authorized**
+
+LOT2-02 (SLM-253) activation requires: SLM-251 (LOT1-02) provides a qualified faithful causal checkpoint/recipe and continued explicit control, and SLM-252 (LOT2-01) selects or bounds the supervision timing/readout routing. The LOT1-02 launch gate reports 'not_authorized' (LOT1-01 disposition 'not_authorized'): no faithful K x c model path, curriculum, Stage 0 parent, or continued-explicit control exists, and SLM-249's oracle ceiling is not positive. Closing not_authorized in plan-only/bounded-diagnostic mode; no training, factorial, intervention, or systems code is added by this disposition.
+
+## Upstream chain
+
+- LOT1-02 launch gate (SLM-251): `not_authorized`
+- LOT1-01 activation gate (SLM-250): `not_authorized`
+- Activation requirement: SLM-251 (LOT1-02) provides a qualified faithful causal checkpoint/recipe and continued explicit control, and SLM-252 (LOT2-01) selects or bounds the supervision timing/readout routing.
+
+## Non-goals honored
+
+No training campaign, factorial, readout/decoder, intervention, systems measurement, or production default change. This disposition is itself the deliverable while the upstream activation gate is unmet.

src/slm_training/harnesses/experiments/lot_downstream_gate.py

@@ -78,6 +78,19 @@ def to_dict(self) -> dict[str, Any]:
             "control, curriculum, and fairness manifests."
         ),
     ),
+    "SLM-253": DownstreamIssueSpec(
+        linear_issue="SLM-253",
+        alias="LOT2-02",
+        title="Compare independent-token PCL with structured, set-valued, and block-autoregressive semantic readouts",
+        gate_contract_id="structured-latent-readout-gate-v1",
+        slug="lot2-02-structured-readout",
+        activation_requirement=(
+            "SLM-251 (LOT1-02) provides a qualified faithful causal "
+            "checkpoint/recipe and continued explicit control, and SLM-252 "
+            "(LOT2-01) selects or bounds the supervision timing/readout "
+            "routing."
+        ),
+    ),
 }
 
 

src/slm_training/resources/versions.json

@@ -1912,7 +1912,7 @@
       ]
     },
     "harness.experiments": {
-      "version": "v118",
+      "version": "v119",
       "kind": "harness",
       "paths": [
         "scripts/run_slm298_capacity_context_curriculum.py",
@@ -1921,6 +1921,11 @@
         "tests/test_scripts/test_run_slm298_capacity_context_curriculum.py"
       ],
       "history": [
+        {
+          "version": "v119",
+          "date": "2026-07-25",
+          "note": "register SLM-253 LOT2-02 in the LOT downstream gate registry; closes not_authorized off the unmet LOT1-02 launch gate"
+        },
         {
           "version": "v118",
           "date": "2026-07-25",
@@ -1981,6 +1986,11 @@
           "date": "2026-07-25",
           "note": "add SLM-300 AP-015 self-context exposure-bias curriculum manifest, policy-origin-mixture wiring/fixture harness, and mixture-zero legacy-equivalence invariant"
         },
+        {
+          "version": "v112",
+          "date": "2026-07-25",
+          "note": "register SLM-253 LOT2-02 in the LOT downstream gate registry; closes not_authorized off the unmet LOT1-02 launch gate"
+        },
         {
           "version": "v111",
           "date": "2026-07-25",
@@ -9796,17 +9806,29 @@
       ]
     },
     "harness.experiments.lot_downstream_gate": {
-      "version": "v1",
+      "version": "v2",
       "kind": "gate",
       "paths": [
-        "src/slm_training/harnesses/experiments/lot_downstream_gate.py",
+        "docs/design/iter-slm252-lot2-01-not-authorized-20260725.json",
+        "docs/design/iter-slm252-lot2-01-not-authorized-20260725.md",
+        "docs/design/iter-slm253-lot2-02-not-authorized-20260725.json",
+        "docs/design/iter-slm253-lot2-02-not-authorized-20260725.md",
         "scripts/evaluate_lot_downstream_gate.py",
+        "src/slm_training/harnesses/experiments/lot_downstream_gate.py",
         "tests/test_harnesses/experiments/test_lot_downstream_gate.py",
-        "tests/test_scripts/test_evaluate_lot_downstream_gate.py",
-        "docs/design/iter-slm252-lot2-01-not-authorized-20260725.json",
-        "docs/design/iter-slm252-lot2-01-not-authorized-20260725.md"
+        "tests/test_scripts/test_evaluate_lot_downstream_gate.py"
       ],
       "history": [
+        {
+          "version": "v2",
+          "date": "2026-07-25",
+          "note": "add SLM-253 LOT2-02 registry entry + not_authorized iter docs (structured-latent-readout-gate-v1)"
+        },
+        {
+          "version": "v2",
+          "date": "2026-07-25",
+          "note": "add SLM-253 LOT2-02 registry entry + not_authorized iter docs (structured-latent-readout-gate-v1)"
+        },
         {
           "version": "v1",
           "date": "2026-07-25",

tests/test_harnesses/experiments/test_lot_downstream_gate.py

@@ -97,3 +97,14 @@ def test_render_markdown_covers_chain() -> None:
     assert "SLM-252" in markdown
     assert "not_authorized" in markdown
     assert "LOT1-02" in markdown
+
+
+def test_slm253_real_contracts_are_not_authorized() -> None:
+    """LOT2-02 additionally requires LOT2-01's selected routing; with the
+    LOT1 chain unmet there is no faithful checkpoint or routing contract.
+    """
+    fidelity, trace = _real_contracts()
+    contract = evaluate_downstream_gate(DOWNSTREAM_ISSUES["SLM-253"], fidelity, trace)
+
+    assert contract.verdict == NOT_AUTHORIZED
+    assert contract.contract_id == "structured-latent-readout-gate-v1"

tests/test_scripts/test_evaluate_lot_downstream_gate.py

@@ -37,3 +37,12 @@ def test_run_against_explicit_contract_paths(tmp_path: Path) -> None:
     markdown = (out / "lot2_01_supervision_routing_gate.md").read_text()
     assert "SLM-252" in markdown
     assert "not_authorized" in markdown
+
+
+def test_slm253_run_reports_not_authorized(tmp_path: Path) -> None:
+    out = tmp_path / "gate253"
+    rc = evaluate_lot_downstream_gate.main(["--issue", "SLM-253", "--out", str(out)])
+    assert rc == 0
+    data = json.loads((out / "lot2_02_structured_readout_gate.json").read_text())
+    assert data["verdict"] == "not_authorized"
+    assert data["issue"]["alias"] == "LOT2-02"