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, 14 deletions

diff --git a/vendor/rustix/src/fs/sync.rs b/vendor/rustix/src/fs/sync.rs
deleted file mode 100644
index cb5f0704..00000000
--- a/vendor/rustix/src/fs/sync.rs
+++ /dev/null
@@ -1,14 +0,0 @@
-use crate::backend;
-
-/// `sync`—Flush cached filesystem data for all filesystems.
-///
-/// # References
-///  - [POSIX]
-///  - [Linux]
-///
-/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/sync.html
-/// [Linux]: https://man7.org/linux/man-pages/man2/sync.2.html
-#[inline]
-pub fn sync() {
-    backend::fs::syscalls::sync();
-}