diff --git a/gitnexus/test/fixtures/scenario-map-recall/README.md b/gitnexus/test/fixtures/scenario-map-recall/README.md
new file mode 100644
index 000000000..d7c0f4809
--- /dev/null
+++ b/gitnexus/test/fixtures/scenario-map-recall/README.md
@@ -0,0 +1,15 @@
+# Recall audit sources
+
+`audit.json` records manually reviewed positive pairs and distinct scenarios from
+PR #3686. The runtime detector still decides whether retrieved candidates are duplicates.
+
+`retired-type-env.ts` preserves 12 pure `stripNullable` callbacks removed from
+`test/unit/type-env.test.ts` after the full detector run on PR #3743 confirmed their
+duplicates in `test/unit/shared-type-extractors.test.ts`. The callbacks and suite titles
+were copied from commit `bd9586e008c6a2dbcd2f15598a3a20c3f2f44f03`; only the import's
+relative path changed. These cases have no hooks or mocks.
+
+The `.ts` suffix keeps this source fixture out of Vitest's `*.test.ts` discovery.
+`recall-audit.test.ts` explicitly parses it, keeping all 82 positive audit pairs
+while the ordinary test suite executes each of these 12 scenarios once.
+The seven other `stripNullable` cases remain in `type-env.test.ts`.
diff --git a/gitnexus/test/fixtures/scenario-map-recall/audit.json b/gitnexus/test/fixtures/scenario-map-recall/audit.json
index 9a96d7f82..8844e8872 100644
--- a/gitnexus/test/fixtures/scenario-map-recall/audit.json
+++ b/gitnexus/test/fixtures/scenario-map-recall/audit.json
@@ -382,73 +382,73 @@
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > strips \"| null\": User | null \u2192 User",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > strips User | null \u2192 User",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > strips User | null \u2192 User",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > strips \"| undefined\": User | undefined \u2192 User",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > strips User | undefined \u2192 User",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > strips User | undefined \u2192 User",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > strips both \"| null | undefined\": User | null | undefined \u2192 User",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > strips User | null | undefined \u2192 User",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > strips User | null | undefined \u2192 User",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > strips nullable suffix: User? \u2192 User",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > strips User? \u2192 User",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > strips User? \u2192 User",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > returns undefined for genuine union: User | Repo",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > refuses genuine union User | Repo \u2192 undefined",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > refuses genuine union User | Repo \u2192 undefined",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > returns undefined for bare \"null\"",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > returns undefined for null alone",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > returns undefined for null alone",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > returns undefined for bare \"undefined\"",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > returns undefined for undefined alone",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > returns undefined for undefined alone",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > returns undefined for bare \"None\"",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > returns undefined for None alone",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > returns undefined for None alone",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > returns undefined for bare \"nil\"",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > returns undefined for nil alone",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > returns undefined for nil alone",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > returns undefined for bare \"void\"",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > returns undefined for void alone",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > returns undefined for void alone",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > returns undefined for empty string",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > returns undefined for empty string",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > returns undefined for empty string",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
     {
       "a": "test/unit/shared-type-extractors.test.ts#stripNullable > returns the type name unchanged when no nullable markers: User \u2192 User",
-      "b": "test/unit/type-env.test.ts#buildTypeEnv > stripNullable > passes through User unchanged",
+      "b": "test/fixtures/scenario-map-recall/retired-type-env.ts#buildTypeEnv > stripNullable > passes through User unchanged",
       "category": "pure-helper",
       "basis": "Same production function, literal inputs and expected values; source callbacks are identical. No enclosing hooks change the input."
     },
diff --git a/gitnexus/test/fixtures/scenario-map-recall/retired-type-env.ts b/gitnexus/test/fixtures/scenario-map-recall/retired-type-env.ts
new file mode 100644
index 000000000..479d919f5
--- /dev/null
+++ b/gitnexus/test/fixtures/scenario-map-recall/retired-type-env.ts
@@ -0,0 +1,56 @@
+// Static input for recall-audit.test.ts; excluded from Vitest discovery by its .ts suffix.
+// Preserves the 12 duplicate callbacks removed from type-env.test.ts (see README.md).
+import { describe, expect, it } from 'vitest';
+import { stripNullable } from '../../../src/core/ingestion/type-extractors/shared.js';
+
+describe('buildTypeEnv', () => {
+  describe('stripNullable', () => {
+    it('strips User | null → User', () => {
+      expect(stripNullable('User | null')).toBe('User');
+    });
+
+    it('strips User | undefined → User', () => {
+      expect(stripNullable('User | undefined')).toBe('User');
+    });
+
+    it('strips User | null | undefined → User', () => {
+      expect(stripNullable('User | null | undefined')).toBe('User');
+    });
+
+    it('strips User? → User', () => {
+      expect(stripNullable('User?')).toBe('User');
+    });
+
+    it('refuses genuine union User | Repo → undefined', () => {
+      expect(stripNullable('User | Repo')).toBeUndefined();
+    });
+
+    it('returns undefined for null alone', () => {
+      expect(stripNullable('null')).toBeUndefined();
+    });
+
+    it('returns undefined for undefined alone', () => {
+      expect(stripNullable('undefined')).toBeUndefined();
+    });
+
+    it('returns undefined for None alone', () => {
+      expect(stripNullable('None')).toBeUndefined();
+    });
+
+    it('returns undefined for nil alone', () => {
+      expect(stripNullable('nil')).toBeUndefined();
+    });
+
+    it('returns undefined for void alone', () => {
+      expect(stripNullable('void')).toBeUndefined();
+    });
+
+    it('returns undefined for empty string', () => {
+      expect(stripNullable('')).toBeUndefined();
+    });
+
+    it('passes through User unchanged', () => {
+      expect(stripNullable('User')).toBe('User');
+    });
+  });
+});
diff --git a/gitnexus/test/unit/type-env.test.ts b/gitnexus/test/unit/type-env.test.ts
index fddfdabbb..f396233ca 100644
--- a/gitnexus/test/unit/type-env.test.ts
+++ b/gitnexus/test/unit/type-env.test.ts
@@ -3224,38 +3224,6 @@ svc = App::Models::Service.new
   });
 
   describe('stripNullable', () => {
-    it('strips User | null → User', () => {
-      expect(stripNullable('User | null')).toBe('User');
-    });
-
-    it('strips User | undefined → User', () => {
-      expect(stripNullable('User | undefined')).toBe('User');
-    });
-
-    it('strips User | null | undefined → User', () => {
-      expect(stripNullable('User | null | undefined')).toBe('User');
-    });
-
-    it('strips User? → User', () => {
-      expect(stripNullable('User?')).toBe('User');
-    });
-
-    it('passes through User unchanged', () => {
-      expect(stripNullable('User')).toBe('User');
-    });
-
-    it('refuses genuine union User | Repo → undefined', () => {
-      expect(stripNullable('User | Repo')).toBeUndefined();
-    });
-
-    it('returns undefined for null alone', () => {
-      expect(stripNullable('null')).toBeUndefined();
-    });
-
-    it('returns undefined for empty string', () => {
-      expect(stripNullable('')).toBeUndefined();
-    });
-
     it('strips User | void → User', () => {
       expect(stripNullable('User | void')).toBe('User');
     });
@@ -3272,22 +3240,6 @@ svc = App::Models::Service.new
       expect(stripNullable('User | void | nil')).toBe('User');
     });
 
-    it('returns undefined for None alone', () => {
-      expect(stripNullable('None')).toBeUndefined();
-    });
-
-    it('returns undefined for nil alone', () => {
-      expect(stripNullable('nil')).toBeUndefined();
-    });
-
-    it('returns undefined for void alone', () => {
-      expect(stripNullable('void')).toBeUndefined();
-    });
-
-    it('returns undefined for undefined alone', () => {
-      expect(stripNullable('undefined')).toBeUndefined();
-    });
-
     it('strips nullable suffix with spaces: User ? → User', () => {
       expect(stripNullable(' User? ')).toBe('User');
     });