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, 20 deletions

diff --git a/vendor/rustix/src/fs/sendfile.rs b/vendor/rustix/src/fs/sendfile.rs
deleted file mode 100644
index db3d6022..00000000
--- a/vendor/rustix/src/fs/sendfile.rs
+++ /dev/null
@@ -1,20 +0,0 @@
-use crate::{backend, io};
-use backend::fd::AsFd;
-
-/// `sendfile(out_fd, in_fd, offset, count)`—Transfer data between file
-/// descriptors.
-///
-/// # References
-///  - [Linux]
-///
-/// [Linux]: https://man7.org/linux/man-pages/man2/sendfile.2.html
-#[cfg(linux_kernel)]
-#[inline]
-pub fn sendfile<OutFd: AsFd, InFd: AsFd>(
-    out_fd: OutFd,
-    in_fd: InFd,
-    offset: Option<&mut u64>,
-    count: usize,
-) -> io::Result<usize> {
-    backend::fs::syscalls::sendfile(out_fd.as_fd(), in_fd.as_fd(), offset, count)
-}