feat(db): mesh data model — meshes, members, invites, audit log

- pgSchema "mesh" with 4 tables isolating the peer mesh domain
- Enums: visibility, transport, tier, role
- audit_log is metadata-only (E2E encryption enforced at broker/client)
- Cascade on mesh delete, soft-delete via archivedAt/revokedAt

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

turbo/generators/config.ts

@@ -0,0 +1,9 @@
+import type { PlopTypes } from "@turbo/gen";
+
+import { createPackageGenerator } from "./templates/package/generator";
+
+const generators = [createPackageGenerator];
+
+export default function generator(plop: PlopTypes.NodePlopAPI): void {
+  generators.forEach((gen) => gen(plop));
+}