feat(core): admit v2 skill guidance (#30843)

packages/core/src/database/migration/20260605042240_add_context_epoch_agent.ts

@@ -0,0 +1,11 @@
+import { Effect } from "effect"
+import type { DatabaseMigration } from "../migration"
+
+export default {
+  id: "20260605042240_add_context_epoch_agent",
+  up(tx) {
+    return Effect.gen(function* () {
+      yield* tx.run(`ALTER TABLE \`session_context_epoch\` ADD \`agent\` text DEFAULT 'build' NOT NULL;`)
+    })
+  },
+} satisfies DatabaseMigration.Migration