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, 19 deletions

diff --git a/vendor/smallvec/src/arbitrary.rs b/vendor/smallvec/src/arbitrary.rs
deleted file mode 100644
index cbdfcb0e..00000000
--- a/vendor/smallvec/src/arbitrary.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-use crate::{Array, SmallVec};
-use arbitrary::{Arbitrary, Unstructured};
-
-impl<'a, A: Array> Arbitrary<'a> for SmallVec<A>
-where
-    <A as Array>::Item: Arbitrary<'a>,
-{
-    fn arbitrary(u: &mut Unstructured<'a>) -> arbitrary::Result<Self> {
-        u.arbitrary_iter()?.collect()
-    }
-
-    fn arbitrary_take_rest(u: Unstructured<'a>) -> arbitrary::Result<Self> {
-        u.arbitrary_take_rest_iter()?.collect()
-    }
-
-    fn size_hint(depth: usize) -> (usize, Option<usize>) {
-        arbitrary::size_hint::and(<usize as Arbitrary>::size_hint(depth), (0, None))
-    }
-}