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, 78 deletions

diff --git a/vendor/rustversion/src/token.rs b/vendor/rustversion/src/token.rs
deleted file mode 100644
index ebb6f1c0..00000000
--- a/vendor/rustversion/src/token.rs
+++ /dev/null
@@ -1,78 +0,0 @@
-use crate::error::{Error, Result};
-use crate::iter::Iter;
-use proc_macro::{Delimiter, Group, Ident, Literal, Span, TokenTree};
-
-pub fn parse_punct(iter: Iter, ch: char) -> Result<()> {
-    match iter.next() {
-        Some(TokenTree::Punct(ref punct)) if punct.as_char() == ch => Ok(()),
-        unexpected => {
-            let span = unexpected
-                .as_ref()
-                .map_or_else(Span::call_site, TokenTree::span);
-            Err(Error::new(span, format!("expected `{}`", ch)))
-        }
-    }
-}
-
-pub fn parse_optional_punct(iter: Iter, ch: char) -> Option<()> {
-    match iter.peek() {
-        Some(TokenTree::Punct(punct)) if punct.as_char() == ch => iter.next().map(drop),
-        _ => None,
-    }
-}
-
-pub fn parse_optional_keyword(iter: Iter, keyword: &str) -> Option<Span> {
-    match iter.peek() {
-        Some(TokenTree::Ident(ident)) if ident.to_string() == keyword => {
-            Some(iter.next().unwrap().span())
-        }
-        _ => None,
-    }
-}
-
-pub fn parse_literal(iter: Iter) -> Result<Literal> {
-    match iter.next() {
-        Some(TokenTree::Literal(literal)) => Ok(literal),
-        unexpected => {
-            let span = unexpected
-                .as_ref()
-                .map_or_else(Span::call_site, TokenTree::span);
-            Err(Error::new(span, "expected literal"))
-        }
-    }
-}
-
-pub fn parse_paren(introducer: &Ident, iter: Iter) -> Result<Group> {
-    match iter.peek() {
-        Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::Parenthesis => {
-            match iter.next() {
-                Some(TokenTree::Group(group)) => Ok(group),
-                _ => unreachable!(),
-            }
-        }
-        Some(unexpected) => Err(Error::new(unexpected.span(), "expected `(`")),
-        None => Err(Error::new(
-            introducer.span(),
-            format!("expected `(` after `{}`", introducer),
-        )),
-    }
-}
-
-pub fn parse_optional_paren(iter: Iter) -> Option<Group> {
-    match iter.peek() {
-        Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::Parenthesis => {
-            match iter.next() {
-                Some(TokenTree::Group(group)) => Some(group),
-                _ => unreachable!(),
-            }
-        }
-        _ => None,
-    }
-}
-
-pub fn parse_end(iter: Iter) -> Result<()> {
-    match iter.next() {
-        None => Ok(()),
-        Some(unexpected) => Err(Error::new(unexpected.span(), "unexpected token")),
-    }
-}