refactor(schema): extract public event definitions (#33579)

packages/schema/src/vcs-event.ts

@@ -0,0 +1,13 @@
+export * as VcsEvent from "./vcs-event"
+
+import { Schema } from "effect"
+import { Event } from "./event"
+
+export const BranchUpdated = Event.define({
+  type: "vcs.branch.updated",
+  schema: {
+    branch: Schema.optional(Schema.String),
+  },
+})
+
+export const Definitions = Event.inventory(BranchUpdated)