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, 33 deletions

diff --git a/vendor/itertools/README.md b/vendor/itertools/README.md
deleted file mode 100644
index 46acc3fc..00000000
--- a/vendor/itertools/README.md
+++ /dev/null
@@ -1,33 +0,0 @@
-# Itertools
-
-Extra iterator adaptors, functions and macros.
-
-Please read the [API documentation here](https://docs.rs/itertools/).
-
-How to use with Cargo:
-
-```toml
-[dependencies]
-itertools = "0.14.0"
-```
-
-How to use in your crate:
-
-```rust
-use itertools::Itertools;
-```
-
-## How to contribute
-If you're not sure what to work on, try checking the [help wanted](https://github.com/rust-itertools/itertools/issues?q=is%3Aopen+is%3Aissue+label%3A%22help+wanted%22) label.
-
-See our [CONTRIBUTING.md](https://github.com/rust-itertools/itertools/blob/master/CONTRIBUTING.md) for a detailed guide.
-
-## License
-
-Dual-licensed to be compatible with the Rust project.
-
-Licensed under the Apache License, Version 2.0
-https://www.apache.org/licenses/LICENSE-2.0 or the MIT license
-https://opensource.org/licenses/MIT, at your
-option. This file may not be copied, modified, or distributed
-except according to those terms.