diff --git a/scripts/verify-real-ghidra-dol.mjs b/scripts/verify-real-ghidra-dol.mjs
index bdc7a5444d..ebfcb64b07 100644
--- a/scripts/verify-real-ghidra-dol.mjs
+++ b/scripts/verify-real-ghidra-dol.mjs
@@ -1,8 +1,7 @@
 #!/usr/bin/env node
 import assert from "node:assert/strict";
 import { execFile } from "node:child_process";
-import { readFile, mkdtemp, mkdir, rm } from "node:fs/promises";
-import { tmpdir } from "node:os";
+import { readFile, mkdir } from "node:fs/promises";
 import { join } from "node:path";
 import { fileURLToPath } from "node:url";
 import { promisify } from "node:util";
@@ -34,6 +33,7 @@ import {
   assertVerifierCleanupComplete,
 } from "./lib/verifier-run.mjs";
 import { withVerifierCleanup } from "./lib/verifier-cleanup.mjs";
+import { VerifierFixture } from "./lib/verifier-fixture.mjs";
 
 // Optional cross-target lane. No tool acquisition and no target execution.
 if (process.argv.length !== 2)
@@ -59,7 +59,17 @@ if (installation.status !== "available")
 const execute = promisify(execFile);
 const entrypoint = fileURLToPath(new URL("./rea.mjs", import.meta.url));
 const run = createVerifierRun();
-const workspace = await mkdtemp(join(tmpdir(), "rea-dol-proof-"));
+const workspaceFixture = await VerifierFixture.open({
+  prefix: "rea-dol-proof-",
+  // Ghidra children use the workspace as TMPDIR; a plain root admits them on every host.
+  private: false,
+});
+const workspace = workspaceFixture.path;
+// A failed run keeps its workspace for diagnosis; the fixture records why.
+const retainWorkspace = (message, options) => {
+  workspaceFixture.retain(message);
+  return new Error(message, options);
+};
 const runtime = join(workspace, "runtime");
 await mkdir(runtime);
 const baseEnv = {
@@ -309,11 +319,11 @@ try {
     },
   ]);
 } catch (cause) {
-  throw new Error(
+  throw retainWorkspace(
     `GameCube DOL verification failed; retained workspace: ${workspace}`,
     { cause },
   );
 }
 assert.ok(completed, "Verifier completion was not observed");
-await rm(workspace, { recursive: true, force: true });
+await workspaceFixture.release();
 console.log(JSON.stringify({ ...completed, fixtures: reports }, null, 2));
diff --git a/scripts/verify-real-ghidra-m68k.mjs b/scripts/verify-real-ghidra-m68k.mjs
index 17d9b26b65..d3e91e6bf1 100644
--- a/scripts/verify-real-ghidra-m68k.mjs
+++ b/scripts/verify-real-ghidra-m68k.mjs
@@ -1,14 +1,7 @@
 import assert from "node:assert/strict";
 import { execFile } from "node:child_process";
 import { createHash } from "node:crypto";
-import {
-  mkdir,
-  mkdtemp,
-  readFile,
-  readdir,
-  rm,
-  writeFile,
-} from "node:fs/promises";
+import { mkdir, readFile, readdir, writeFile } from "node:fs/promises";
 import { join } from "node:path";
 import { fileURLToPath } from "node:url";
 import { promisify } from "node:util";
@@ -21,6 +14,7 @@ import {
   requireMcpOutput,
 } from "./lib/mcp-verifier-results.mjs";
 import { createVerifierRun, completeVerifierRun } from "./lib/verifier-run.mjs";
+import { VerifierFixture } from "./lib/verifier-fixture.mjs";
 
 if (process.argv.length !== 2)
   throw new Error("Usage: node scripts/verify-real-ghidra-m68k.mjs");
@@ -57,7 +51,18 @@ assert.equal(
   "7679358409efee4c5c2465f9a47158c4d49e0415ba12b3170898440db7ea0bc9",
 );
 await mkdir(join(root, "build"), { recursive: true });
-const workspace = await mkdtemp(join(root, "build", "rea-m68k-proof-"));
+const workspaceFixture = await VerifierFixture.open({
+  prefix: "rea-m68k-proof-",
+  // Ghidra children use the workspace as TMPDIR; a plain root admits them on every host.
+  private: false,
+  parent: join(root, "build"),
+});
+const workspace = workspaceFixture.path;
+// A failed run keeps its workspace for diagnosis; the fixture records why.
+const retainWorkspace = (message, options) => {
+  workspaceFixture.retain(message);
+  return new Error(message, options);
+};
 const runtime = join(workspace, "runtime");
 await mkdir(runtime);
 const path = join(workspace, "image.bin");
@@ -257,6 +262,9 @@ try {
   };
 } catch (cause) {
   if (stderr) process.stderr.write(stderr);
+  workspaceFixture.retain(
+    `m68k verification failed; retained workspace: ${workspace}`,
+  );
   throw cause;
 } finally {
   try {
@@ -265,16 +273,20 @@ try {
     await transport.close();
   }
 }
-assert.deepEqual(
-  await readdir(runtime),
-  [],
-  `Runtime resources survived server shutdown; retained workspace: ${workspace}`,
-);
+const survivors = await readdir(runtime);
+if (survivors.length > 0)
+  throw retainWorkspace(
+    `Runtime resources survived server shutdown (${survivors.join(", ")}); retained workspace: ${workspace}`,
+  );
 const verifierRun = await completeVerifierRun(run);
-assert.equal(verifierRun.process_lineage.status, "verified");
-assert.deepEqual(verifierRun.process_lineage.descendants, []);
-// Keep the workspace for diagnosis unless verification and cleanup both pass.
-await rm(workspace, { recursive: true, force: true });
+if (
+  verifierRun.process_lineage.status !== "verified" ||
+  verifierRun.process_lineage.descendants.length !== 0
+)
+  throw retainWorkspace(
+    `Cleanup unverified; retained diagnostic workspace: ${workspace}`,
+  );
+await workspaceFixture.release();
 process.stdout.write(
   JSON.stringify({ verifier_run: verifierRun, ...report }) + "\n",
 );
diff --git a/scripts/verify-real-ghidra-mips-relocatable.mjs b/scripts/verify-real-ghidra-mips-relocatable.mjs
index 95c3a8b8e0..4762271640 100755
--- a/scripts/verify-real-ghidra-mips-relocatable.mjs
+++ b/scripts/verify-real-ghidra-mips-relocatable.mjs
@@ -2,8 +2,7 @@
 import assert from "node:assert/strict";
 import { execFile } from "node:child_process";
 import { createHash } from "node:crypto";
-import { mkdtemp, mkdir, readFile, rm } from "node:fs/promises";
-import { tmpdir } from "node:os";
+import { mkdir, readFile } from "node:fs/promises";
 import { join } from "node:path";
 import { fileURLToPath } from "node:url";
 import { promisify } from "node:util";
@@ -21,6 +20,7 @@ import {
 } from "../tests/conformance/ghidra/mips-relocatable-checks.mjs";
 import { requireMcpOperationResult } from "./lib/mcp-verifier-results.mjs";
 import { createVerifierRun, completeVerifierRun } from "./lib/verifier-run.mjs";
+import { VerifierFixture } from "./lib/verifier-fixture.mjs";
 
 // Optional cross-target lane for ET_REL objects. No tool acquisition, no
 // linking and no target execution.
@@ -48,7 +48,17 @@ if (installation.status !== "available")
 const execute = promisify(execFile);
 const entrypoint = fileURLToPath(new URL("./rea.mjs", import.meta.url));
 const run = createVerifierRun();
-const workspace = await mkdtemp(join(tmpdir(), "rea-mips-rel-proof-"));
+const workspaceFixture = await VerifierFixture.open({
+  prefix: "rea-mips-rel-proof-",
+  // Ghidra children use the workspace as TMPDIR; a plain root admits them on every host.
+  private: false,
+});
+const workspace = workspaceFixture.path;
+// A failed run keeps its workspace for diagnosis; the fixture records why.
+const retainWorkspace = (message, options) => {
+  workspaceFixture.retain(message);
+  return new Error(message, options);
+};
 const runtime = join(workspace, "runtime");
 await mkdir(runtime);
 const env = {
@@ -320,14 +330,14 @@ if (
   completed.process_lineage.status !== "verified" ||
   completed.process_lineage.descendants.length !== 0
 )
-  throw new Error(
+  throw retainWorkspace(
     `Cleanup unverified; retained diagnostic workspace: ${workspace}`,
     { cause: primaryFailure },
   );
 if (primaryFailure !== undefined)
-  throw new Error(
+  throw retainWorkspace(
     `MIPS relocatable verification failed; retained workspace: ${workspace}`,
     { cause: primaryFailure },
   );
-await rm(workspace, { recursive: true, force: true });
+await workspaceFixture.release();
 console.log(JSON.stringify({ ...completed, fixtures: reports }, null, 2));
diff --git a/scripts/verify-real-ghidra-mips-shared.mjs b/scripts/verify-real-ghidra-mips-shared.mjs
index 133306de32..8a60952c54 100644
--- a/scripts/verify-real-ghidra-mips-shared.mjs
+++ b/scripts/verify-real-ghidra-mips-shared.mjs
@@ -1,8 +1,7 @@
 #!/usr/bin/env node
 import assert from "node:assert/strict";
 import { execFile } from "node:child_process";
-import { mkdtemp, mkdir, readFile, rm, writeFile } from "node:fs/promises";
-import { tmpdir } from "node:os";
+import { mkdir, readFile, writeFile } from "node:fs/promises";
 import { join } from "node:path";
 import { promisify } from "node:util";
 import { Client } from "@modelcontextprotocol/client";
@@ -16,6 +15,7 @@ import {
   requireMcpToolError,
 } from "./lib/mcp-verifier-results.mjs";
 import { createVerifierRun, completeVerifierRun } from "./lib/verifier-run.mjs";
+import { VerifierFixture } from "./lib/verifier-fixture.mjs";
 
 if (
   process.env.GHIDRA_INSTALL_DIR === undefined ||
@@ -26,7 +26,17 @@ if (
   );
 const execute = promisify(execFile);
 const run = createVerifierRun();
-const workspace = await mkdtemp(join(tmpdir(), "rea-mips-shared-proof-"));
+const workspaceFixture = await VerifierFixture.open({
+  prefix: "rea-mips-shared-proof-",
+  // Ghidra children use the workspace as TMPDIR; a plain root admits them on every host.
+  private: false,
+});
+const workspace = workspaceFixture.path;
+// A failed run keeps its workspace for diagnosis; the fixture records why.
+const retainWorkspace = (message, options) => {
+  workspaceFixture.retain(message);
+  return new Error(message, options);
+};
 const runtime = join(workspace, "runtime");
 await mkdir(runtime);
 const env = {
@@ -328,13 +338,16 @@ if (
   completed.process_lineage.status !== "verified" ||
   completed.process_lineage.descendants.length !== 0
 )
-  throw new Error(`Cleanup unverified; retained workspace: ${workspace}`, {
-    cause: failure,
-  });
+  throw retainWorkspace(
+    `Cleanup unverified; retained workspace: ${workspace}`,
+    {
+      cause: failure,
+    },
+  );
 if (failure !== undefined)
-  throw new Error(
+  throw retainWorkspace(
     `MIPS16 shared verification failed; retained workspace: ${workspace}`,
     { cause: failure },
   );
-await rm(workspace, { recursive: true, force: true });
+await workspaceFixture.release();
 console.log(JSON.stringify({ ...completed, fixtures: reports }, null, 2));
diff --git a/scripts/verify-real-ghidra-mips.mjs b/scripts/verify-real-ghidra-mips.mjs
index 4405d155b9..4208a01f1e 100644
--- a/scripts/verify-real-ghidra-mips.mjs
+++ b/scripts/verify-real-ghidra-mips.mjs
@@ -3,15 +3,12 @@ import assert from "node:assert/strict";
 import { execFile } from "node:child_process";
 import { createHash } from "node:crypto";
 import {
-  mkdtemp,
   mkdir,
   readFile,
   readdir,
   realpath,
-  rm,
   writeFile,
 } from "node:fs/promises";
-import { tmpdir } from "node:os";
 import { basename, join, relative } from "node:path";
 import { fileURLToPath } from "node:url";
 import { promisify } from "node:util";
@@ -48,6 +45,7 @@ import {
 } from "./lib/mcp-verifier-results.mjs";
 import { createVerifierRun, completeVerifierRun } from "./lib/verifier-run.mjs";
 import { runOwnedCommand } from "../dist/process/OwnedCommand.js";
+import { VerifierFixture } from "./lib/verifier-fixture.mjs";
 
 // Optional cross-target lane. No tool acquisition and no target execution.
 const mode = process.argv[2];
@@ -78,7 +76,17 @@ if (installation.status !== "available")
 const execute = promisify(execFile);
 const entrypoint = fileURLToPath(new URL("./rea.mjs", import.meta.url));
 const run = createVerifierRun();
-const workspace = await mkdtemp(join(tmpdir(), "rea-mips-proof-"));
+const workspaceFixture = await VerifierFixture.open({
+  prefix: "rea-mips-proof-",
+  // Ghidra children use the workspace as TMPDIR; a plain root admits them on every host.
+  private: false,
+});
+const workspace = workspaceFixture.path;
+// A failed run keeps its workspace for diagnosis; the fixture records why.
+const retainWorkspace = (message, options) => {
+  workspaceFixture.retain(message);
+  return new Error(message, options);
+};
 const runtime = join(workspace, "runtime");
 await mkdir(runtime);
 const env = {
@@ -892,16 +900,16 @@ if (
   completed.process_lineage.status !== "verified" ||
   completed.process_lineage.descendants.length !== 0
 )
-  throw new Error(
+  throw retainWorkspace(
     `Cleanup unverified; retained diagnostic workspace: ${workspace}`,
     { cause: primaryFailure },
   );
 if (primaryFailure !== undefined)
-  throw new Error(
+  throw retainWorkspace(
     `MIPS verification failed; retained workspace: ${workspace}`,
     {
       cause: primaryFailure,
     },
   );
-await rm(workspace, { recursive: true, force: true });
+await workspaceFixture.release();
 console.log(JSON.stringify({ ...completed, fixtures: reports }, null, 2));
diff --git a/scripts/verify-real-ghidra-ppc.mjs b/scripts/verify-real-ghidra-ppc.mjs
index ac131580ea..aab8b8630f 100644
--- a/scripts/verify-real-ghidra-ppc.mjs
+++ b/scripts/verify-real-ghidra-ppc.mjs
@@ -2,8 +2,7 @@
 import assert from "node:assert/strict";
 import { execFile } from "node:child_process";
 import { createHash } from "node:crypto";
-import { mkdtemp, mkdir, readFile, rm } from "node:fs/promises";
-import { tmpdir } from "node:os";
+import { mkdir, readFile } from "node:fs/promises";
 import { join } from "node:path";
 import { fileURLToPath } from "node:url";
 import { promisify } from "node:util";
@@ -23,6 +22,7 @@ import { inspectVerifierGhidraInstallation } from "./lib/ghidra-installation-ins
 import { buildPowerPcFixture } from "../tests/conformance/ghidra/ppc-fixture.mjs";
 import { requireMcpOperationResult } from "./lib/mcp-verifier-results.mjs";
 import { createVerifierRun, completeVerifierRun } from "./lib/verifier-run.mjs";
+import { VerifierFixture } from "./lib/verifier-fixture.mjs";
 
 // Optional cross-target lane. No tool acquisition and no target execution.
 if (process.argv.length !== 2)
@@ -47,7 +47,17 @@ if (installation.status !== "available")
 const execute = promisify(execFile);
 const entrypoint = fileURLToPath(new URL("./rea.mjs", import.meta.url));
 const run = createVerifierRun();
-const workspace = await mkdtemp(join(tmpdir(), "rea-ppc-proof-"));
+const workspaceFixture = await VerifierFixture.open({
+  prefix: "rea-ppc-proof-",
+  // Ghidra children use the workspace as TMPDIR; a plain root admits them on every host.
+  private: false,
+});
+const workspace = workspaceFixture.path;
+// A failed run keeps its workspace for diagnosis; the fixture records why.
+const retainWorkspace = (message, options) => {
+  workspaceFixture.retain(message);
+  return new Error(message, options);
+};
 const runtime = join(workspace, "runtime");
 await mkdir(runtime);
 const env = {
@@ -303,16 +313,16 @@ if (
   completed.process_lineage.status !== "verified" ||
   completed.process_lineage.descendants.length !== 0
 )
-  throw new Error(
+  throw retainWorkspace(
     `Cleanup unverified; retained diagnostic workspace: ${workspace}`,
     { cause: primaryFailure },
   );
 if (primaryFailure !== undefined)
-  throw new Error(
+  throw retainWorkspace(
     `PowerPC verification failed; retained workspace: ${workspace}`,
     {
       cause: primaryFailure,
     },
   );
-await rm(workspace, { recursive: true, force: true });
+await workspaceFixture.release();
 console.log(JSON.stringify({ ...completed, fixtures: reports }, null, 2));
diff --git a/scripts/verify-real-ghidra-riscv.mjs b/scripts/verify-real-ghidra-riscv.mjs
index c33cbfb21e..5ebc58881c 100644
--- a/scripts/verify-real-ghidra-riscv.mjs
+++ b/scripts/verify-real-ghidra-riscv.mjs
@@ -3,15 +3,7 @@ import { schemaVerifierEnvironment } from "./lib/mcp-verification-environment.mj
 import assert from "node:assert/strict";
 import { execFile } from "node:child_process";
 import { createHash } from "node:crypto";
-import {
-  mkdtemp,
-  mkdir,
-  readFile,
-  readdir,
-  rm,
-  writeFile,
-} from "node:fs/promises";
-import { tmpdir } from "node:os";
+import { mkdir, readFile, readdir, writeFile } from "node:fs/promises";
 import { join } from "node:path";
 import { fileURLToPath } from "node:url";
 import { promisify } from "node:util";
@@ -42,6 +34,7 @@ import {
   requireMcpToolError,
 } from "./lib/mcp-verifier-results.mjs";
 import { createVerifierRun, completeVerifierRun } from "./lib/verifier-run.mjs";
+import { VerifierFixture } from "./lib/verifier-fixture.mjs";
 
 if (process.argv.length !== 2)
   throw new Error("Usage: node scripts/verify-real-ghidra-riscv.mjs");
@@ -67,7 +60,17 @@ assert.equal(installation.providerVersion, "12.1.4");
 const execute = promisify(execFile);
 const entrypoint = fileURLToPath(new URL("./rea.mjs", import.meta.url));
 const run = createVerifierRun();
-const workspace = await mkdtemp(join(tmpdir(), "rea-riscv-proof-"));
+const workspaceFixture = await VerifierFixture.open({
+  prefix: "rea-riscv-proof-",
+  // Ghidra children use the workspace as TMPDIR; a plain root admits them on every host.
+  private: false,
+});
+const workspace = workspaceFixture.path;
+// A failed run keeps its workspace for diagnosis; the fixture records why.
+const retainWorkspace = (message, options) => {
+  workspaceFixture.retain(message);
+  return new Error(message, options);
+};
 const runtime = join(workspace, "runtime");
 await mkdir(runtime);
 const env = {
@@ -563,20 +566,23 @@ if (
   completed.process_lineage.status !== "verified" ||
   completed.process_lineage.descendants.length !== 0
 )
-  throw new Error(`Cleanup unverified; retained workspace: ${workspace}`, {
-    cause: failure,
-  });
+  throw retainWorkspace(
+    `Cleanup unverified; retained workspace: ${workspace}`,
+    {
+      cause: failure,
+    },
+  );
 if (failure !== undefined)
-  throw new Error(
+  throw retainWorkspace(
     `RISC-V verification failed; retained workspace: ${workspace}; MCP stderr: ${stderr}`,
     { cause: failure },
   );
-assert.deepEqual(
-  await readdir(runtime),
-  [],
-  `Runtime resources survived server shutdown; retained workspace: ${workspace}`,
-);
-await rm(workspace, { recursive: true, force: true });
+const survivors = await readdir(runtime);
+if (survivors.length > 0)
+  throw retainWorkspace(
+    `Runtime resources survived server shutdown (${survivors.join(", ")}); retained workspace: ${workspace}`,
+  );
+await workspaceFixture.release();
 console.log(
   JSON.stringify(
     {
diff --git a/scripts/verify/architecture-guard-baselines.json b/scripts/verify/architecture-guard-baselines.json
index a8cfb43a9e..764f3aa482 100644
--- a/scripts/verify/architecture-guard-baselines.json
+++ b/scripts/verify/architecture-guard-baselines.json
@@ -423,15 +423,8 @@
     "scripts/verify-real-cutter.mjs": 1,
     "scripts/verify-real-ghidra-address-context.mjs": 1,
     "scripts/verify-real-ghidra-checkpoints.mjs": 1,
-    "scripts/verify-real-ghidra-dol.mjs": 1,
     "scripts/verify-real-ghidra-function-bundle.mjs": 1,
-    "scripts/verify-real-ghidra-m68k.mjs": 1,
-    "scripts/verify-real-ghidra-mips-relocatable.mjs": 1,
-    "scripts/verify-real-ghidra-mips-shared.mjs": 1,
-    "scripts/verify-real-ghidra-mips.mjs": 1,
-    "scripts/verify-real-ghidra-ppc.mjs": 1,
     "scripts/verify-real-ghidra-project-coverage.mjs": 1,
-    "scripts/verify-real-ghidra-riscv.mjs": 1,
     "scripts/verify-real-ghidra-swift.mjs": 1,
     "scripts/verify-real-ghidra-switch.mjs": 1,
     "scripts/verify-real-ghidra.mjs": 1,