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, 51 deletions

diff --git a/vendor/digest/src/dev/xof.rs b/vendor/digest/src/dev/xof.rs
deleted file mode 100644
index 9e5d07a0..00000000
--- a/vendor/digest/src/dev/xof.rs
+++ /dev/null
@@ -1,51 +0,0 @@
-use crate::ExtendableOutputReset;
-use core::fmt::Debug;
-
-/// Resettable XOF test
-pub fn xof_reset_test<D>(input: &[u8], output: &[u8]) -> Option<&'static str>
-where
-    D: ExtendableOutputReset + Default + Debug + Clone,
-{
-    let mut hasher = D::default();
-    let mut buf = [0u8; 1024];
-    let buf = &mut buf[..output.len()];
-    // Test that it works when accepting the message all at once
-    hasher.update(input);
-    let mut hasher2 = hasher.clone();
-    hasher.finalize_xof_into(buf);
-    if buf != output {
-        return Some("whole message");
-    }
-    buf.iter_mut().for_each(|b| *b = 0);
-
-    // Test if reset works correctly
-    hasher2.reset();
-    hasher2.update(input);
-    hasher2.finalize_xof_reset_into(buf);
-    if buf != output {
-        return Some("whole message after reset");
-    }
-    buf.iter_mut().for_each(|b| *b = 0);
-
-    // Test that it works when accepting the message in chunks
-    for n in 1..core::cmp::min(17, input.len()) {
-        let mut hasher = D::default();
-        for chunk in input.chunks(n) {
-            hasher.update(chunk);
-            hasher2.update(chunk);
-        }
-        hasher.finalize_xof_into(buf);
-        if buf != output {
-            return Some("message in chunks");
-        }
-        buf.iter_mut().for_each(|b| *b = 0);
-
-        hasher2.finalize_xof_reset_into(buf);
-        if buf != output {
-            return Some("message in chunks");
-        }
-        buf.iter_mut().for_each(|b| *b = 0);
-    }
-
-    None
-}