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/shared/src/schema/sort.ts

@@ -0,0 +1,8 @@
+import * as z from "zod";
+
+export const sortSchema = z.object({
+  id: z.string(),
+  desc: z.boolean().optional().default(false),
+});
+
+export type SortPayload = z.infer<typeof sortSchema>;