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, 29 deletions

diff --git a/vendor/rustix/COPYRIGHT b/vendor/rustix/COPYRIGHT
deleted file mode 100644
index a841525e..00000000
--- a/vendor/rustix/COPYRIGHT
+++ /dev/null
@@ -1,29 +0,0 @@
-Short version for non-lawyers:
-
-`rustix` is triple-licensed under Apache 2.0 with the LLVM Exception,
-Apache 2.0, and MIT terms.
-
-
-Longer version:
-
-Copyrights in the `rustix` project are retained by their contributors.
-No copyright assignment is required to contribute to the `rustix`
-project.
-
-Some files include code derived from Rust's `libstd`; see the comments in
-the code for details.
-
-Except as otherwise noted (below and/or in individual files), `rustix`
-is licensed under:
-
- - the Apache License, Version 2.0, with the LLVM Exception
-   <LICENSE-Apache-2.0_WITH_LLVM-exception> or
-   <http://llvm.org/foundation/relicensing/LICENSE.txt>
- - the Apache License, Version 2.0
-   <LICENSE-APACHE> or
-   <http://www.apache.org/licenses/LICENSE-2.0>,
- - or the MIT license
-   <LICENSE-MIT> or
-   <http://opensource.org/licenses/MIT>,
-
-at your option.