feat(core-shared/conformance): defineFeature helper + manifest types

packages/core-shared/src/conformance/define-feature.ts

@@ -0,0 +1,38 @@
+/**
+ * Per-use-case manifest entry. Declares what the use case does at the contract
+ * level: whether it mutates state, what audit events it emits, what cross-feature
+ * events it publishes or consumes. The conformance system reads these to
+ * derive binding-slot types and to verify code against manifest declarations.
+ */
+export type UseCaseManifest = {
+  readonly mutates: boolean;
+  readonly audits: readonly string[];
+  readonly publishes: readonly string[];
+  readonly consumes: readonly string[];
+};
+
+/**
+ * The feature-level manifest. One per feature package, conventionally exported
+ * as `<featureName>Manifest` from `src/feature.manifest.ts`.
+ */
+export type FeatureManifest = {
+  readonly name: string;
+  readonly requiredCores: readonly string[];
+  readonly useCases: { readonly [k: string]: UseCaseManifest };
+  readonly realtimeChannels: readonly string[];
+  readonly jobs: readonly string[];
+};
+
+/**
+ * Identity helper that exists purely to widen the input type to satisfy
+ * `FeatureManifest` while preserving the literal types of the `as const`
+ * input. Downstream types (`ProductionUseCase<I, O, M>`) consume the
+ * preserved literals to derive binding-slot brand requirements.
+ *
+ * Usage:
+ *
+ *   export const authManifest = defineFeature({ name: "auth", ... } as const);
+ */
+export function defineFeature<const M extends FeatureManifest>(manifest: M): M {
+  return manifest;
+}