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, 66 deletions

diff --git a/vendor/unicode-normalization/src/replace.rs b/vendor/unicode-normalization/src/replace.rs
deleted file mode 100644
index 3ab2a573..00000000
--- a/vendor/unicode-normalization/src/replace.rs
+++ /dev/null
@@ -1,66 +0,0 @@
-// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-use core::{
-    fmt::{self, Write},
-    iter::FusedIterator,
-};
-use tinyvec::ArrayVec;
-
-/// External iterator for replacements for a string's characters.
-#[derive(Clone)]
-pub struct Replacements<I> {
-    iter: I,
-    // At this time, the longest replacement sequence has length 2, so we just
-    // need buffer space for 1 codepoint.
-    buffer: Option<char>,
-}
-
-#[inline]
-pub fn new_cjk_compat_variants<I: Iterator<Item = char>>(iter: I) -> Replacements<I> {
-    Replacements { iter, buffer: None }
-}
-
-impl<I: Iterator<Item = char>> Iterator for Replacements<I> {
-    type Item = char;
-
-    #[inline]
-    fn next(&mut self) -> Option<char> {
-        if let Some(c) = self.buffer.take() {
-            return Some(c);
-        }
-
-        match self.iter.next() {
-            Some(ch) => {
-                // At this time, the longest replacement sequence has length 2.
-                let mut buffer = ArrayVec::<[char; 2]>::new();
-                super::char::decompose_cjk_compat_variants(ch, |d| buffer.push(d));
-                self.buffer = buffer.get(1).copied();
-                Some(buffer[0])
-            }
-            None => None,
-        }
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        let (lower, _) = self.iter.size_hint();
-        (lower, None)
-    }
-}
-
-impl<I: Iterator<Item = char> + FusedIterator> FusedIterator for Replacements<I> {}
-
-impl<I: Iterator<Item = char> + Clone> fmt::Display for Replacements<I> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        for c in self.clone() {
-            f.write_char(c)?;
-        }
-        Ok(())
-    }
-}