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>

packages/db/src/scripts/seed.ts

@@ -0,0 +1,12 @@
+import { logger } from "@turbostarter/shared/logger";
+
+function main() {
+  /**
+   * Place your seeding logic here
+   */
+
+  logger.info("Database seeded successfully!");
+  process.exit(0);
+}
+
+main();