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, 18 deletions

diff --git a/vendor/tinystr/src/error.rs b/vendor/tinystr/src/error.rs
deleted file mode 100644
index ea1ab212..00000000
--- a/vendor/tinystr/src/error.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-// This file is part of ICU4X. For terms of use, please see the file
-// called LICENSE at the top level of the ICU4X source tree
-// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
-
-use displaydoc::Display;
-
-impl core::error::Error for ParseError {}
-
-#[derive(Display, Debug, PartialEq, Eq)]
-#[non_exhaustive]
-pub enum ParseError {
-    #[displaydoc("found string of larger length {len} when constructing string of length {max}")]
-    TooLong { max: usize, len: usize },
-    #[displaydoc("tinystr types do not support strings with null bytes")]
-    ContainsNull,
-    #[displaydoc("attempted to construct TinyAsciiStr from a non-ASCII string")]
-    NonAscii,
-}