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, 56 deletions

diff --git a/vendor/rustix/src/process/pidfd_getfd.rs b/vendor/rustix/src/process/pidfd_getfd.rs
deleted file mode 100644
index 1be215e0..00000000
--- a/vendor/rustix/src/process/pidfd_getfd.rs
+++ /dev/null
@@ -1,56 +0,0 @@
-//! The [`pidfd_getfd`] function and supporting types.
-
-#![allow(unsafe_code)]
-use crate::fd::OwnedFd;
-use crate::{backend, ffi, io};
-use backend::fd::{AsFd, RawFd};
-
-/// Raw file descriptor in another process.
-///
-/// A distinct type alias is used here to inform the user that normal file
-/// descriptors from the calling process should not be used. The provided file
-/// descriptor is used by the kernel as the index into the file descriptor
-/// table of an entirely different process.
-pub type ForeignRawFd = RawFd;
-
-bitflags::bitflags! {
-    /// All flags are reserved for future use.
-    #[repr(transparent)]
-    #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
-    pub struct PidfdGetfdFlags: ffi::c_uint {
-        /// <https://docs.rs/bitflags/*/bitflags/#externally-defined-flags>
-        const _ = !0;
-    }
-}
-
-/// `syscall(SYS_pidfd_getfd, pidfd, flags)`—Obtain a duplicate of another
-/// process' file descriptor.
-///
-/// # References
-///  - [Linux]
-///
-/// # Warning
-///
-/// This function is generally safe for the calling process, but it can impact
-/// the target process in unexpected ways. If you want to ensure that Rust I/O
-/// safety assumptions continue to hold in the target process, then the target
-/// process must have communicated the file description number to the calling
-/// process from a value of a type that implements `AsRawFd`, and the target
-/// process must not drop that value until after the calling process has
-/// returned from `pidfd_getfd`.
-///
-/// When `pidfd_getfd` is used to debug the target, or the target is not a Rust
-/// application, or `pidfd_getfd` is used in any other way, then extra care
-/// should be taken to avoid unexpected behaviour or crashes.
-///
-/// For further details, see the references above.
-///
-/// [Linux]: https://man7.org/linux/man-pages/man2/pidfd_getfd.2.html
-#[inline]
-pub fn pidfd_getfd<Fd: AsFd>(
-    pidfd: Fd,
-    targetfd: ForeignRawFd,
-    flags: PidfdGetfdFlags,
-) -> io::Result<OwnedFd> {
-    backend::process::syscalls::pidfd_getfd(pidfd.as_fd(), targetfd, flags)
-}