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, 32 deletions

diff --git a/vendor/thiserror-impl/src/fallback.rs b/vendor/thiserror-impl/src/fallback.rs
deleted file mode 100644
index e9c429ba..00000000
--- a/vendor/thiserror-impl/src/fallback.rs
+++ /dev/null
@@ -1,32 +0,0 @@
-use crate::expand::call_site_ident;
-use proc_macro2::TokenStream;
-use quote::quote;
-use syn::DeriveInput;
-
-pub(crate) fn expand(input: &DeriveInput, error: syn::Error) -> TokenStream {
-    let ty = call_site_ident(&input.ident);
-    let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
-
-    let error = error.to_compile_error();
-
-    quote! {
-        #error
-
-        #[allow(unused_qualifications)]
-        #[automatically_derived]
-        impl #impl_generics ::thiserror::__private::Error for #ty #ty_generics #where_clause
-        where
-            // Work around trivial bounds being unstable.
-            // https://github.com/rust-lang/rust/issues/48214
-            for<'workaround> #ty #ty_generics: ::core::fmt::Debug,
-        {}
-
-        #[allow(unused_qualifications)]
-        #[automatically_derived]
-        impl #impl_generics ::core::fmt::Display for #ty #ty_generics #where_clause {
-            fn fmt(&self, __formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
-                ::core::unreachable!()
-            }
-        }
-    }
-}