feat(core-shared): add analyticsEvents field to UseCaseManifest

Add optional `analyticsEvents?: readonly string[]` to `UseCaseManifest`
in `define-feature.ts` so manifests can declare which analytics events a
use case emits. Field defaults to absent (treated as []) — all existing
manifests remain valid without changes.

Update the feature generator template to emit `analyticsEvents: []` so
newly scaffolded features are analytics-declaration-ready from day one.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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

@@ -11,6 +11,7 @@ export type UseCaseManifest = {
   readonly audits: readonly string[];
   readonly publishes: readonly string[];
   readonly consumes: readonly string[];
+  readonly analyticsEvents?: readonly string[];
 };
 
 /**

turbo/generators/templates/feature/src/feature.manifest.ts.hbs

@@ -20,6 +20,7 @@ export const {{camelCase name}}Manifest = defineFeature({
       audits: [],
       publishes: [],
       consumes: [],
+      analyticsEvents: [],
     },
   },
   realtimeChannels: [],