fix(devx): declare import-prerequisite's loaders so a .mts gate can import them without TS7016

`check-exported-any-returns.mts` is inside the ROOT tsc program, where an
untyped `.mjs` import is TS7016 — measured, not assumed: converting it added
exactly one error (169 vs the 168 the same tree reports with the unconverted
file), and `@objectstack/spec-monorepo` is a shrink-only ratchet. The sidecar is
the shape three root scripts already use for the same reason, and
`check:declaration-mirrors` covers it by discovery.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012zGPuVVX3deAx9LdjK8jCk

Author: claude

scripts/import-prerequisite.d.mts

@@ -0,0 +1,62 @@
+// Types for the two dependency loaders `import-prerequisite.mjs` publishes to
+// the gates that import it.
+//
+// The module itself stays `.mjs` for the reason its three sibling mirrors
+// state: `pre-commit` and the gates invoke these scripts with bare `node`, and
+// every root script here is authored that way. What needs the declaration is
+// the other direction -- a TypeScript-authored gate (`.mts`) importing a loader
+// from inside the ROOT tsc program, where an untyped `.mjs` import is TS7016.
+// `check-exported-any-returns.mts` is the first such consumer; without this
+// file its conversion would have added one error to the `@objectstack/spec-
+// monorepo` entry of `check:type-check-debt`, a shrink-only ratchet.
+//
+// PARTIAL on purpose, the `check-regen-pending.d.mts` shape: the module also
+// exports the exit-code constants, the classifier and its self-test, and
+// omitting them cannot fail green -- a consumer importing an undeclared name
+// gets TS2305, which is loud and immediate. Keep this file in step with the
+// module by hand; `check:declaration-mirrors` checks name, kind and required
+// arity, never types.
+//
+// ⛔ The return type is `any` BY MEASUREMENT, not by omission: what these
+// return is whatever the loaded package exports, and the 27 `.mjs` call sites
+// already bind it untyped. A consumer that wants the real namespace types
+// declares them itself -- `check-exported-any-returns.mts` keeps an erased
+// `import type TS from 'typescript'` beside the runtime binding for exactly
+// that, and a `typescript`-shaped return here would be a lie at every other
+// call site (`yaml`, `semver`, `eslint`, `github-slugger`).
+
+/**
+ * Load a dependency, or print a named `PREREQUISITE NOT MET` diagnosis and exit
+ * `EXIT_PREREQUISITE_NOT_MET` (3). Resolves to the module NAMESPACE.
+ *
+ * @param specifier The bare specifier, e.g. `'@typescript-eslint/parser'`.
+ * @param load `() => import('@typescript-eslint/parser')`, written in the CALLER
+ *   so the failing resolution is the caller's own.
+ * @param importerUrl The caller's `import.meta.url`.
+ * @param options `measures` is what the gate would have judged, in the gate's
+ *   own words -- the one half of the refusal text that is never shared.
+ */
+export function requireDependency(
+  specifier: string,
+  load: () => Promise<unknown>,
+  importerUrl: string,
+  options?: { measures?: string },
+): Promise<any>;
+
+/**
+ * `requireDependency` for the DEFAULT export -- the shape `import ts from
+ * 'typescript'` had. Reads `.default` strictly rather than falling back to the
+ * namespace.
+ *
+ * @param specifier The bare specifier, e.g. `'typescript'`.
+ * @param load `() => import('typescript')`, written in the CALLER.
+ * @param importerUrl The caller's `import.meta.url`.
+ * @param options `measures` is what the gate would have judged, in the gate's
+ *   own words.
+ */
+export function requireDefaultExport(
+  specifier: string,
+  load: () => Promise<unknown>,
+  importerUrl: string,
+  options?: { measures?: string },
+): Promise<any>;