- **feat(compression):** update the vendored **GCF** codec behind the **Headroom** engine to spec **v3.2 (nested flattening)** ([#6837](https://github.com/diegosouzapw/OmniRoute/issues/6837)). Homogeneous arrays whose rows carry nested objects/arrays now tabularize via `>`-prefixed path fields instead of a low-yield per-row fallback, so nested MCP tool-result rows (`meta:{...}`, `tags:[...]`) compact like flat rows. On representative shapes the update takes deeply-nested payloads the old codec left near-uncompressed from ~3% to ~32% vs JSON (k8s pods, `cl100k_base`), with shallow-nested rows seeing a small bump and flat arrays unchanged. Re-vendored from current gcf-typescript (zero runtime deps, MIT, SPDX-marked, generic-profile only); also folds in the `[N]:` inline-array quoting fix and canonical decimal formatting. Round-trip stays lossless (order-insensitive), and the decoder is hardened against prototype pollution (a `__proto__`/`constructor` path segment never mutates `Object.prototype`, and keys shadowing built-ins like `toString` now round-trip correctly instead of misparsing). Regression guard: `tests/unit/compression/headroom-smartcrusher.test.ts` (deep-nested + prototype-pollution cases).