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, 18 deletions

diff --git a/vendor/ref-cast/tests/test_custom.rs b/vendor/ref-cast/tests/test_custom.rs
deleted file mode 100644
index 73d9bd69..00000000
--- a/vendor/ref-cast/tests/test_custom.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-#[forbid(unsafe_code)]
-mod forbid_unsafe {
-    use ref_cast::{ref_cast_custom, RefCastCustom};
-
-    #[derive(RefCastCustom)]
-    #[repr(transparent)]
-    pub struct Custom(#[allow(dead_code)] str);
-
-    impl Custom {
-        #[ref_cast_custom]
-        pub fn new(s: &str) -> &Custom;
-    }
-}
-
-#[test]
-fn test_forbid_unsafe() {
-    forbid_unsafe::Custom::new("...");
-}