diff --git a/packages/lint/src/lazy-deps.test.ts b/packages/lint/src/lazy-deps.test.ts
index d209cddc776..fb1dec22892 100644
--- a/packages/lint/src/lazy-deps.test.ts
+++ b/packages/lint/src/lazy-deps.test.ts
@@ -1,5 +1,4 @@
 // Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
-// test-budget: 30 — whole-package import: the in-process case imports the whole @objectstack/lint barrel cold, so the file's floor is vitest's transform of that graph and of every inlined @objectstack/spec dist bundle it reaches, and the two built-dist probes each spawn node once; slowest CI reading 18.0 s (hourly run 38267594064) x 1.25, rounded up
 //
 // Boot-path contract: importing @objectstack/lint must NOT load its heavy,
 // gate-only dependencies. The package sits on the kernel boot path, while each
diff --git a/packages/lint/src/runtime-lazy-deps.test.ts b/packages/lint/src/runtime-lazy-deps.test.ts
index d8e06f055a4..2cbe3abb70c 100644
--- a/packages/lint/src/runtime-lazy-deps.test.ts
+++ b/packages/lint/src/runtime-lazy-deps.test.ts
@@ -1,5 +1,4 @@
 // Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
-// test-budget: 30 — whole-package import: the in-process cases import the @objectstack/lint/runtime entry cold, which reaches the whole gate graph, so the file's floor is vitest's transform of it and of every inlined @objectstack/spec dist bundle it reaches, and the three built-dist probes each spawn node once; slowest CI reading 19.2 s (hourly run 38314183560) x 1.25, rounded up
 //
 // The kernel boot-path contract for `@objectstack/lint/runtime` (#4463).
 //
diff --git a/packages/lint/src/vitest-spec-external.test.ts b/packages/lint/src/vitest-spec-external.test.ts
new file mode 100644
index 00000000000..061aaec872b
--- /dev/null
+++ b/packages/lint/src/vitest-spec-external.test.ts
@@ -0,0 +1,56 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+//
+// Positive control for `test.server.deps.external` in ../vitest.config.ts.
+//
+// That entry hands the linked `@objectstack/spec` dist to Node instead of
+// vite's transform. Its pattern is matched against the module's REALPATH, and
+// a pattern that matches nothing is silent: the suite stays green and only
+// gets slower. So this file asks the one question that tells the two apart —
+// is the spec module these sources import the SAME instance Node's own loader
+// holds?
+//
+// - Externalised: vitest's runner loads the dist with a native `import()`, so
+//   Node's loader holds that module, and a native load of the same file
+//   returns that very instance — its exports are identical objects.
+// - Inlined (the pattern stopped matching): vite evaluates its own copy of the
+//   dist, and the native load builds a separate one — every export is a
+//   different object, and the identity assertions below go red.
+//
+// The native load is `require()` of the ESM file (Node 22's require(esm),
+// which shares the ESM loader's module map) through `createRequire`, so vite
+// cannot rewrite it; vitest's evaluator gives a `new Function` `import()` no
+// dynamic-import callback. The file is the one the package's `exports` map
+// names for an ESM import, taken from the linked package root.
+import { readFileSync, realpathSync } from 'node:fs';
+import { createRequire } from 'node:module';
+import { join, resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { describe, expect, it } from 'vitest';
+import { defineStack } from '@objectstack/spec';
+import { ObjectSchema } from '@objectstack/spec/data';
+
+const HERE = fileURLToPath(new URL('.', import.meta.url));
+// The package's own node_modules link — the same one these sources resolve.
+const SPEC_ROOT = realpathSync(resolve(HERE, '../node_modules/@objectstack/spec'));
+
+const nativeRequire = createRequire(import.meta.url);
+
+function nativeEsmEntry(subpath: '.' | './data'): Record<string, unknown> {
+  const manifest = JSON.parse(readFileSync(join(SPEC_ROOT, 'package.json'), 'utf8'));
+  const target: string = manifest.exports[subpath].import.default;
+  return nativeRequire(join(SPEC_ROOT, target)) as Record<string, unknown>;
+}
+
+describe('@objectstack/spec is loaded by Node, not inlined by vite', () => {
+  it('the root entry is the native module instance', () => {
+    const native = nativeEsmEntry('.');
+    expect(typeof defineStack).toBe('function');
+    expect(defineStack).toBe(native.defineStack);
+  });
+
+  it('a subpath entry is the native module instance', () => {
+    const native = nativeEsmEntry('./data');
+    expect(ObjectSchema).toBeDefined();
+    expect(ObjectSchema).toBe(native.ObjectSchema);
+  });
+});
diff --git a/packages/lint/vitest.config.ts b/packages/lint/vitest.config.ts
index 5e0591efc44..4ecbe245f44 100644
--- a/packages/lint/vitest.config.ts
+++ b/packages/lint/vitest.config.ts
@@ -1,9 +1,11 @@
 // Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
 
-// This config exists for exactly one setting; everything else stays on
+// This config exists for exactly two settings; everything else stays on
 // vitest's defaults, deliberately — a key added here re-specifies behaviour
 // for every test file in the package (packages/cli/vitest.config.ts's header
-// records the incident that taught that).
+// records the incident that taught that). Both settings are package-wide on
+// purpose: each removes a mechanism every file here is exposed to, rather
+// than tuning one file.
 import { defineConfig } from 'vitest/config';
 
 export default defineConfig({
@@ -15,5 +17,30 @@ export default defineConfig({
     // Mechanism + measured costs: examples/app-showcase/vitest.config.ts.
     // Enforced repo-wide by scripts/check-console-intercept-disarm.mjs.
     disableConsoleIntercept: true,
+    server: {
+      deps: {
+        // Load the linked `@objectstack/spec` dist with Node, not through
+        // vite's transform. Vitest's default `external` is node_modules-only,
+        // judged on a module's REALPATH, and a pnpm-linked workspace package's
+        // realpath is `packages/spec/dist/…` — so without this nearly every
+        // file here (lint imports spec's root and nine subpaths) inlined about
+        // 33 MB of built `.mjs`, and the first file to import a lint entry paid
+        // ~10 s of its cold transform. The import resolves through `exports`
+        // to `dist/` either way, so this changes only who evaluates that dist,
+        // never which bytes are under test.
+        //
+        // ⚠️ The pattern must match the realpath; a name-shaped one
+        // (`@objectstack/spec`) matches nothing, silently — see
+        // packages/cli/vitest.config.ts. The positive control is
+        // `src/vitest-spec-external.test.ts`, red the moment this stops
+        // matching.
+        //
+        // Cost: an externalised module cannot be `vi.mock`ed. The census taken
+        // when this landed found zero `vi.mock` / `vi.doMock` / `vi.hoisted`
+        // sites in this package; a later test that needs to mock spec must
+        // move this entry, not work around it.
+        external: [/[\\/]packages[\\/]spec[\\/]dist[\\/]/],
+      },
+    },
   },
 });