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>

apps/web/.env

@@ -0,0 +1,7 @@
+
+# MinIO S3 (local dev)
+S3_REGION="us-east-1"
+S3_BUCKET="uploads"
+S3_ENDPOINT="http://localhost:9000"
+S3_ACCESS_KEY_ID="minioadmin"
+S3_SECRET_ACCESS_KEY="minioadmin"