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, 17 deletions

diff --git a/vendor/string_cache/tests/small-stack.rs b/vendor/string_cache/tests/small-stack.rs
deleted file mode 100644
index bb607af6..00000000
--- a/vendor/string_cache/tests/small-stack.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-// Regression test for https://github.com/servo/html5ever/issues/393
-//
-// Create a dynamic atom − causing initialization of the global hash map −
-// in a thread that has a small stack.
-//
-// This is a separate test program rather than a `#[test] fn` among others
-// to make sure that nothing else has already initialized the map in this process.
-fn main() {
-    std::thread::Builder::new()
-        .stack_size(50_000)
-        .spawn(|| {
-            let _atom = string_cache::DefaultAtom::from("12345678");
-        })
-        .unwrap()
-        .join()
-        .unwrap()
-}