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, 46 deletions

diff --git a/vendor/rustix/src/mm/msync.rs b/vendor/rustix/src/mm/msync.rs
deleted file mode 100644
index c6723436..00000000
--- a/vendor/rustix/src/mm/msync.rs
+++ /dev/null
@@ -1,46 +0,0 @@
-//! The `msync` function.
-//!
-//! # Safety
-//!
-//! `msync` operates on a raw pointer. Some forms of `msync` may mutate the
-//! memory or have other side effects.
-#![allow(unsafe_code)]
-
-use crate::{backend, io};
-use core::ffi::c_void;
-
-pub use backend::mm::types::MsyncFlags;
-
-/// `msync(addr, len, flags)`—Synchronizes a memory-mapping with its backing
-/// storage.
-///
-/// # Safety
-///
-/// `addr` must be a valid pointer to memory that is appropriate to call
-/// `msync` on. Some forms of `msync` may mutate the memory or evoke a variety
-/// of side-effects on the mapping and/or the file.
-///
-/// # References
-///  - [POSIX]
-///  - [Linux]
-///  - [Apple]
-///  - [FreeBSD]
-///  - [NetBSD]
-///  - [OpenBSD]
-///  - [DragonFly BSD]
-///  - [illumos]
-///  - [glibc]
-///
-/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/msync.html
-/// [Linux]: https://man7.org/linux/man-pages/man2/msync.2.html
-/// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/msync.2.html
-/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=msync&sektion=2
-/// [NetBSD]: https://man.netbsd.org/msync.2
-/// [OpenBSD]: https://man.openbsd.org/msync.2
-/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=msync&section=2
-/// [illumos]: https://illumos.org/man/3C/msync
-/// [glibc]: https://sourceware.org/glibc/manual/latest/html_node/Memory_002dmapped-I_002fO.html#index-msync
-#[inline]
-pub unsafe fn msync(addr: *mut c_void, len: usize, flags: MsyncFlags) -> io::Result<()> {
-    backend::mm::syscalls::msync(addr, len, flags)
-}