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, 83 deletions

diff --git a/vendor/itertools/src/repeatn.rs b/vendor/itertools/src/repeatn.rs
deleted file mode 100644
index d86ad9fa..00000000
--- a/vendor/itertools/src/repeatn.rs
+++ /dev/null
@@ -1,83 +0,0 @@
-use std::iter::FusedIterator;
-
-/// An iterator that produces *n* repetitions of an element.
-///
-/// See [`repeat_n()`](crate::repeat_n) for more information.
-#[must_use = "iterators are lazy and do nothing unless consumed"]
-#[derive(Clone, Debug)]
-pub struct RepeatN<A> {
-    pub(crate) elt: Option<A>,
-    n: usize,
-}
-
-/// Create an iterator that produces `n` repetitions of `element`.
-pub fn repeat_n<A>(element: A, n: usize) -> RepeatN<A>
-where
-    A: Clone,
-{
-    if n == 0 {
-        RepeatN { elt: None, n }
-    } else {
-        RepeatN {
-            elt: Some(element),
-            n,
-        }
-    }
-}
-
-impl<A> Iterator for RepeatN<A>
-where
-    A: Clone,
-{
-    type Item = A;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.n > 1 {
-            self.n -= 1;
-            self.elt.as_ref().cloned()
-        } else {
-            self.n = 0;
-            self.elt.take()
-        }
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        (self.n, Some(self.n))
-    }
-
-    fn fold<B, F>(self, mut init: B, mut f: F) -> B
-    where
-        F: FnMut(B, Self::Item) -> B,
-    {
-        match self {
-            Self { elt: Some(elt), n } => {
-                debug_assert!(n > 0);
-                init = (1..n).map(|_| elt.clone()).fold(init, &mut f);
-                f(init, elt)
-            }
-            _ => init,
-        }
-    }
-}
-
-impl<A> DoubleEndedIterator for RepeatN<A>
-where
-    A: Clone,
-{
-    #[inline]
-    fn next_back(&mut self) -> Option<Self::Item> {
-        self.next()
-    }
-
-    #[inline]
-    fn rfold<B, F>(self, init: B, f: F) -> B
-    where
-        F: FnMut(B, Self::Item) -> B,
-    {
-        self.fold(init, f)
-    }
-}
-
-impl<A> ExactSizeIterator for RepeatN<A> where A: Clone {}
-
-impl<A> FusedIterator for RepeatN<A> where A: Clone {}