build(deps): return vitest to 4.1.11 so mutation testing exercises mutants

.github/dependabot.yml

@@ -21,6 +21,11 @@ updates:
       # Version 10 of the preset needs conventional-changelog-writer 9, but @semantic-release/release-notes-generator still loads writer 8, so generating notes throws and no release is published. Lift this once that plugin depends on writer 9.
       - dependency-name: "conventional-changelog-conventionalcommits"
         update-types: ["version-update:semver-major"]
+      # @stryker-mutator/vitest-runner 10.0.0 does not exercise mutants under vitest 5: the same package scores about 4 there and about 94 on vitest 4, so every mutation result on vitest 5 is vacuous. Lift these once the runner supports vitest 5 and a package's score is unchanged by the bump.
+      - dependency-name: "vitest"
+        update-types: ["version-update:semver-major"]
+      - dependency-name: "@vitest/*"
+        update-types: ["version-update:semver-major"]
   - package-ecosystem: github-actions
     directory: /
     schedule:

packages/targets/graph-web/vitest.config.ts

@@ -14,6 +14,8 @@ export default defineConfig({
           name: "unit",
           include: ["src/**/*.test.{ts,tsx}", "build/**/*.test.ts"],
           environment: "happy-dom",
+          // Node 25 and later define their own `localStorage` global, which shadows happy-dom's and throws without a storage file. The flag turns that global off so the test environment's window storage is the one tests see.
+          execArgv: ["--no-experimental-webstorage"],
         },
       },
       {

packages/targets/process-graph/package.json

@@ -138,8 +138,8 @@
     "@types/react": "19.3.0",
     "@vanilla-extract/css": "1.21.2",
     "@vanilla-extract/recipes": "0.5.7",
-    "@vitest/browser-playwright": "5.0.3",
-    "@vitest/coverage-v8": "5.0.3",
+    "@vitest/browser-playwright": "4.1.11",
+    "@vitest/coverage-v8": "4.1.11",
     "@xyflow/react": "12.12.0",
     "commander": "15.0.0",
     "drizzle-orm": "1.0.0-rc.4",
@@ -151,7 +151,7 @@
     "react-dom": "19.3.0",
     "tsdown": "0.23.0",
     "typescript": "6.0.3",
-    "vitest": "5.0.3"
+    "vitest": "4.1.11"
   },
   "dependencies": {
     "trilean": "1.7.2",