feat: migrate from Cedar to SpiceDB authorization system

This is a major architectural change that replaces the Cedar policy-based
authorization system with SpiceDB's relation-based authorization.

Key changes:

- Migrate from Rust to Go implementation
- Replace Cedar policies with SpiceDB schema and relationships
- Switch from envoy `ext_authz` with Cedar to SpiceDB permission checks
- Update build system and dependencies for Go ecosystem
- Maintain Envoy integration for external authorization

This change enables more flexible permission modeling through SpiceDB's
Google Zanzibar inspired relation-based system, supporting complex
hierarchical permissions that were difficult to express in Cedar.

Breaking change: Existing Cedar policies and Rust-based configuration
will no longer work and need to be migrated to SpiceDB schema.

1 files changed, 0 insertions, 43 deletions

diff --git a/vendor/tower-layer/README.md b/vendor/tower-layer/README.md
deleted file mode 100644
index 48f9dbb7..00000000
--- a/vendor/tower-layer/README.md
+++ /dev/null
@@ -1,43 +0,0 @@
-# Tower Layer
-
-Decorates a [Tower] `Service`, transforming either the request or the response.
-
-[![Crates.io][crates-badge]][crates-url]
-[![Documentation][docs-badge]][docs-url]
-[![Documentation (master)][docs-master-badge]][docs-master-url]
-[![MIT licensed][mit-badge]][mit-url]
-[![Build Status][actions-badge]][actions-url]
-[![Discord chat][discord-badge]][discord-url]
-
-[crates-badge]: https://img.shields.io/crates/v/tower-layer.svg
-[crates-url]: https://crates.io/crates/tower-layer
-[docs-badge]: https://docs.rs/tower-layer/badge.svg
-[docs-url]: https://docs.rs/tower-layer
-[docs-master-badge]: https://img.shields.io/badge/docs-master-blue
-[docs-master-url]: https://tower-rs.github.io/tower/tower_layer
-[mit-badge]: https://img.shields.io/badge/license-MIT-blue.svg
-[mit-url]: LICENSE
-[actions-badge]: https://github.com/tower-rs/tower/workflows/CI/badge.svg
-[actions-url]:https://github.com/tower-rs/tower/actions?query=workflow%3ACI
-[discord-badge]: https://img.shields.io/discord/500028886025895936?logo=discord&label=discord&logoColor=white
-[discord-url]: https://discord.gg/EeF3cQw
-
-## Overview
-
-Often, many of the pieces needed for writing network applications can be
-reused across multiple services. The `Layer` trait can be used to write
-reusable components that can be applied to very different kinds of services;
-for example, it can be applied to services operating on different protocols,
-and to both the client and server side of a network transaction.
-
-## License
-
-This project is licensed under the [MIT license](LICENSE).
-
-### Contribution
-
-Unless you explicitly state otherwise, any contribution intentionally submitted
-for inclusion in Tower by you, shall be licensed as MIT, without any additional
-terms or conditions.
-
-[Tower]: https://crates.io/crates/tower
\ No newline at end of file