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, 115 deletions

diff --git a/vendor/writeable/src/parts_write_adapter.rs b/vendor/writeable/src/parts_write_adapter.rs
deleted file mode 100644
index eacf3a2c..00000000
--- a/vendor/writeable/src/parts_write_adapter.rs
+++ /dev/null
@@ -1,115 +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 crate::*;
-
-/// A wrapper around a type implementing [`fmt::Write`] that implements [`PartsWrite`].
-#[derive(Debug)]
-#[allow(clippy::exhaustive_structs)] // newtype
-pub struct CoreWriteAsPartsWrite<W: fmt::Write + ?Sized>(pub W);
-
-impl<W: fmt::Write + ?Sized> fmt::Write for CoreWriteAsPartsWrite<W> {
-    #[inline]
-    fn write_str(&mut self, s: &str) -> fmt::Result {
-        self.0.write_str(s)
-    }
-
-    #[inline]
-    fn write_char(&mut self, c: char) -> fmt::Result {
-        self.0.write_char(c)
-    }
-}
-
-impl<W: fmt::Write + ?Sized> PartsWrite for CoreWriteAsPartsWrite<W> {
-    type SubPartsWrite = CoreWriteAsPartsWrite<W>;
-
-    #[inline]
-    fn with_part(
-        &mut self,
-        _part: Part,
-        mut f: impl FnMut(&mut Self::SubPartsWrite) -> fmt::Result,
-    ) -> fmt::Result {
-        f(self)
-    }
-}
-
-/// A [`Writeable`] that writes out the given part.
-///
-/// # Examples
-///
-/// ```
-/// use writeable::adapters::WithPart;
-/// use writeable::assert_writeable_parts_eq;
-/// use writeable::Part;
-///
-/// // Simple usage:
-///
-/// const PART: Part = Part {
-///     category: "foo",
-///     value: "bar",
-/// };
-///
-/// assert_writeable_parts_eq!(
-///     WithPart {
-///         writeable: "Hello World",
-///         part: PART
-///     },
-///     "Hello World",
-///     [(0, 11, PART)],
-/// );
-///
-/// // Can be nested:
-///
-/// const PART2: Part = Part {
-///     category: "foo2",
-///     value: "bar2",
-/// };
-///
-/// assert_writeable_parts_eq!(
-///     WithPart {
-///         writeable: WithPart {
-///             writeable: "Hello World",
-///             part: PART
-///         },
-///         part: PART2
-///     },
-///     "Hello World",
-///     [(0, 11, PART), (0, 11, PART2)],
-/// );
-/// ```
-#[derive(Debug)]
-#[allow(clippy::exhaustive_structs)] // public adapter
-pub struct WithPart<T: ?Sized> {
-    pub part: Part,
-    pub writeable: T,
-}
-
-impl<T: Writeable + ?Sized> Writeable for WithPart<T> {
-    #[inline]
-    fn write_to<W: fmt::Write + ?Sized>(&self, sink: &mut W) -> fmt::Result {
-        self.writeable.write_to(sink)
-    }
-
-    #[inline]
-    fn write_to_parts<W: PartsWrite + ?Sized>(&self, sink: &mut W) -> fmt::Result {
-        sink.with_part(self.part, |w| self.writeable.write_to_parts(w))
-    }
-
-    #[inline]
-    fn writeable_length_hint(&self) -> LengthHint {
-        self.writeable.writeable_length_hint()
-    }
-
-    #[inline]
-    fn write_to_string(&self) -> Cow<str> {
-        self.writeable.write_to_string()
-    }
-}
-
-impl<T: Writeable + ?Sized> fmt::Display for WithPart<T> {
-    #[inline]
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        Writeable::write_to(&self, f)
-    }
-}