🚚 Home test helpers behind #test-utils/*

src/util/__tests__/ holds shared test helpers, reached from anywhere
in the source tree as `#test-utils/<name>.ts` through
package.json#imports. A bare `~/…` is not a valid imports key — Node
requires `#` — and a direction-free specifier keeps
import/no-relative-parent-imports from ever firing. The `__tests__`
folder name is the pattern tsconfig.build.json already excludes, so
helpers can never ship. Lint scoping: import/no-nodejs-modules off for
the folder (the probe spawns a language server) and
typescript/promise-function-async off to match its promise-returning
style. The LSP probe moves in from scripts/; a smoke test pins the
specifier's resolution and typing without starting a server.

.oxlintrc.json

@@ -22,7 +22,8 @@
         "eslint/sort-imports": "off",
         "import/consistent-type-specifier-style": "off",
         "unicorn/prefer-export-from": "off",
-        "typescript/method-signature-style": "off"
+        "typescript/method-signature-style": "off",
+        "typescript/promise-function-async": "off"
     },
     "options": { "typeAware": true },
     "env": { "builtin": true, "es2024": true, "node": true },
@@ -41,6 +42,12 @@
             "rules": {
                 "import/no-nodejs-modules": "off"
             }
+        },
+        {
+            "files": ["src/util/__tests__/**"],
+            "rules": {
+                "import/no-nodejs-modules": "off"
+            }
         }
     ],
     "ignorePatterns": ["dist", "node_modules", "coverage"]