[codex] classify tests-as-data migration ratchet

docs/briefs/r3-v-tests-as-data-v1-worker.md

@@ -61,7 +61,7 @@ Gate IDs reference [`docs/r3-program-plan.md`](../r3-program-plan.md) §1.8 "Can
 
 ## Implementation slices (suggested PR sequence)
 
-1. **V4-a — Census + mapping:** refresh readiness audit §1; extend predicate coverage map (audit §6 slice 2).
+1. **V4-a — Census + mapping:** refresh readiness audit §1; extend predicate coverage map (audit §6 slice 2). The SG-0 migration-class matcher is transitional: each class-by-class migration PR should remove the corresponding path matcher branch as those Rust paths move to `.dag` `TestClaim` data, and gate #84 close requires the matcher itself to disappear with `EXPECTED_HAND_AUTHORED_TEST` at zero.
 2. **V4-b — First executable port:** satisfy `tests_as_data_demonstration` + shrink SG-0 net (audit §6 slice 3).
 3. **V4-c — Quantifiers + generator:** land when **T4** clears (audit §6 slice 4).
 4. **V4-d — Facet-3 close:** census **0** + cementing discipline satisfied (audit §6 slice 5).

src/v3/compiler/tests/integration/sg0_census_test.rs

@@ -29,7 +29,7 @@
 //! `build.rs` names it. File contents do not participate: a hand-authored
 //! `.rs` that begins with `// AUTO-GENERATED` does not slip through.
 
-use std::collections::BTreeSet;
+use std::collections::{BTreeMap, BTreeSet};
 use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path, PathBuf};
@@ -701,6 +701,94 @@ const EXPECTED_GENERATED_FRAGMENTS: &[&str] = &[
     "src/v3/compiler/tests/integration/parse_corpus_manifest.txt",
 ];
 
+#[derive(Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd)]
+enum TestsAsDataMigrationClass {
+    CompileOrReject,
+    LensOutputEquality,
+    BehavioralObservation,
+    BoundaryHostProcess,
+    CementingV2Oracle,
+    CensusOrRatchet,
+    PropertyBased,
+}
+
+const EXPECTED_TESTS_AS_DATA_MIGRATION_AUDIT_COUNT: usize = 116;
+
+// Transitional gate #84 audit only. As each class migrates to `.dag`
+// `TestClaim` data, remove that class's path matcher branch with the
+// retired Rust paths; when `EXPECTED_HAND_AUTHORED_TEST` reaches zero,
+// this classifier should disappear with it.
+// Match order is load-bearing while this exists: check classification
+// before deleting or reordering a branch, especially broad substring
+// branches such as `contains("sg")`.
+fn tests_as_data_migration_class(path: &str) -> Option<TestsAsDataMigrationClass> {
+    use TestsAsDataMigrationClass::*;
+
+    if path.starts_with("src/v3/compiler/tests/boundary/") {
+        return Some(BoundaryHostProcess);
+    }
+
+    if path.contains("/cementing/")
+        || path.ends_with("lens_behavioral_parity_demonstration_test.rs")
+        || path.ends_with("r3_gate_87_lens_cementing_regen_receipts_test.rs")
+    {
+        return Some(CementingV2Oracle);
+    }
+
+    if path.contains("census")
+        || path.contains("ratchet")
+        || path.contains("bridge")
+        || path.contains("sg")
+        || path.contains("r1c_")
+        || path.contains("v2_oracle")
+        || path.contains("value_body_substrate_mirror")
+        || path.contains("lens_producer_retirement")
+    {
+        return Some(CensusOrRatchet);
+    }
+
+    if path.contains("free_consequences")
+        || path.contains("tc1_")
+        || path.contains("tc2_")
+        || path.contains("tc3_")
+    {
+        return Some(PropertyBased);
+    }
+
+    if path.contains("lens")
+        || path.contains("cost")
+        || path.contains("parallelism")
+        || path.contains("timing")
+        || path.contains("workflow")
+        || path.contains("e6_g1a")
+        || path.contains("lane2_stage_2d")
+    {
+        return Some(LensOutputEquality);
+    }
+
+    if path.contains("anthropic")
+        || path.contains("operation")
+        || path.contains("services")
+        || path.contains("omni")
+        || path.contains("openapi")
+        || path.contains("runtime_evaluator_corpus")
+        || path.contains("self_host_demonstration")
+        || path.contains("t_ci_workflow_as_data_demo")
+        || path.contains("pb1_bootstrap_full_snapshot")
+    {
+        return Some(BehavioralObservation);
+    }
+
+    if path.starts_with("src/v3/compiler/tests/integration/")
+        || path.starts_with("src/v3/compiler/tests/determinism_test.rs")
+        || path.starts_with("src/v3/compiler/tests/integration.rs")
+    {
+        return Some(CompileOrReject);
+    }
+
+    None
+}
+
 fn is_test_path(path: &str) -> bool {
     path.starts_with("src/v3/compiler/tests/")
 }
@@ -957,6 +1045,46 @@ fn sg0_v3_test_hand_authored_subratchet() {
     );
 }
 
+#[test]
+fn sg0_tests_as_data_migration_audit_classifies_test_ratchet() {
+    let mut by_class: BTreeMap<TestsAsDataMigrationClass, Vec<&str>> = BTreeMap::new();
+    let mut unclassified = Vec::new();
+
+    for path in EXPECTED_HAND_AUTHORED_TEST {
+        match tests_as_data_migration_class(path) {
+            Some(class) => by_class.entry(class).or_default().push(*path),
+            None => unclassified.push(*path),
+        }
+    }
+
+    assert!(
+        unclassified.is_empty(),
+        "gate #84 migration audit must classify every hand-authored test path; \
+         unclassified paths: {unclassified:?}"
+    );
+    assert_eq!(
+        EXPECTED_HAND_AUTHORED_TEST.len(),
+        EXPECTED_TESTS_AS_DATA_MIGRATION_AUDIT_COUNT,
+        "gate #84 migration audit count drifted; update the migration-class audit \
+         when the SG-0 hand-authored test ratchet changes"
+    );
+
+    for class in [
+        TestsAsDataMigrationClass::CompileOrReject,
+        TestsAsDataMigrationClass::LensOutputEquality,
+        TestsAsDataMigrationClass::BehavioralObservation,
+        TestsAsDataMigrationClass::BoundaryHostProcess,
+        TestsAsDataMigrationClass::CementingV2Oracle,
+        TestsAsDataMigrationClass::CensusOrRatchet,
+        TestsAsDataMigrationClass::PropertyBased,
+    ] {
+        assert!(
+            by_class.get(&class).is_some_and(|paths| !paths.is_empty()),
+            "gate #84 migration audit lost class coverage for {class:?}"
+        );
+    }
+}
+
 #[test]
 fn sg0_v3_non_test_fragment_subratchet() {
     let misplaced_fragments: Vec<&str> = EXPECTED_HAND_AUTHORED_FRAGMENTS