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, 32 deletions

diff --git a/vendor/petgraph/src/iter_utils.rs b/vendor/petgraph/src/iter_utils.rs
deleted file mode 100644
index 587af84c..00000000
--- a/vendor/petgraph/src/iter_utils.rs
+++ /dev/null
@@ -1,32 +0,0 @@
-pub trait IterUtilsExt: Iterator {
-    /// Return the first element that maps to `Some(_)`, or None if the iterator
-    /// was exhausted.
-    fn ex_find_map<F, R>(&mut self, mut f: F) -> Option<R>
-    where
-        F: FnMut(Self::Item) -> Option<R>,
-    {
-        for elt in self {
-            if let result @ Some(_) = f(elt) {
-                return result;
-            }
-        }
-        None
-    }
-
-    /// Return the last element from the back that maps to `Some(_)`, or
-    /// None if the iterator was exhausted.
-    fn ex_rfind_map<F, R>(&mut self, mut f: F) -> Option<R>
-    where
-        F: FnMut(Self::Item) -> Option<R>,
-        Self: DoubleEndedIterator,
-    {
-        while let Some(elt) = self.next_back() {
-            if let result @ Some(_) = f(elt) {
-                return result;
-            }
-        }
-        None
-    }
-}
-
-impl<I> IterUtilsExt for I where I: Iterator {}