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, 34 deletions

diff --git a/vendor/time/src/error/different_variant.rs b/vendor/time/src/error/different_variant.rs
deleted file mode 100644
index 22e21cb0..00000000
--- a/vendor/time/src/error/different_variant.rs
+++ /dev/null
@@ -1,34 +0,0 @@
-//! Different variant error
-
-use core::fmt;
-
-/// An error type indicating that a [`TryFrom`](core::convert::TryFrom) call failed because the
-/// original value was of a different variant.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub struct DifferentVariant;
-
-impl fmt::Display for DifferentVariant {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "value was of a different variant than required")
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for DifferentVariant {}
-
-impl From<DifferentVariant> for crate::Error {
-    fn from(err: DifferentVariant) -> Self {
-        Self::DifferentVariant(err)
-    }
-}
-
-impl TryFrom<crate::Error> for DifferentVariant {
-    type Error = Self;
-
-    fn try_from(err: crate::Error) -> Result<Self, Self::Error> {
-        match err {
-            crate::Error::DifferentVariant(err) => Ok(err),
-            _ => Err(Self),
-        }
-    }
-}