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>

tooling/eslint/src/next.js

@@ -0,0 +1,16 @@
+import nextPlugin from "@next/eslint-plugin-next";
+
+/** @type {Awaited<import('typescript-eslint').Config>} */
+export default [
+  {
+    files: ["**/*.ts", "**/*.tsx"],
+    plugins: {
+      "@next/next": nextPlugin,
+    },
+    rules: {
+      ...nextPlugin.configs.recommended.rules,
+      ...nextPlugin.configs["core-web-vitals"].rules,
+      "@next/next/no-duplicate-head": "off",
+    },
+  },
+];