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, 42 deletions

diff --git a/src/authorization/server.rs b/src/authorization/server.rs
deleted file mode 100644
index 31bf2af8..00000000
--- a/src/authorization/server.rs
+++ /dev/null
@@ -1,42 +0,0 @@
-use super::cedar_authorizer::CedarAuthorizer;
-use super::check_service::CheckService;
-use envoy_types::ext_authz::v3::pb::AuthorizationServer;
-use std::sync::Arc;
-
-pub struct Server {
-    router: tonic::transport::server::Router,
-}
-
-impl Server {
-    pub fn new<T: super::Authorizer>(authorizer: T) -> Result<Server, Box<dyn std::error::Error>> {
-        let authorization_service =
-            AuthorizationServer::new(CheckService::new(Arc::new(authorizer)));
-
-        Ok(Self::new_with(|mut builder| {
-            builder.add_service(authorization_service)
-        }))
-    }
-
-    pub fn new_with<F>(f: F) -> Server
-    where
-        F: FnOnce(tonic::transport::Server) -> tonic::transport::server::Router,
-    {
-        let builder = tonic::transport::Server::builder()
-            .trace_fn(
-                |req| tracing::info_span!("rpc", method = %req.method(), path = %req.uri().path()),
-            )
-            .timeout(std::time::Duration::from_secs(30));
-        let router = f(builder);
-        Server { router }
-    }
-
-    pub async fn serve(self, addr: std::net::SocketAddr) -> Result<(), tonic::transport::Error> {
-        self.router.serve(addr).await
-    }
-}
-
-impl Default for Server {
-    fn default() -> Self {
-        Self::new(CedarAuthorizer::default()).unwrap()
-    }
-}