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, 86 deletions

diff --git a/vendor/multimap/README.md b/vendor/multimap/README.md
deleted file mode 100644
index 93e745c1..00000000
--- a/vendor/multimap/README.md
+++ /dev/null
@@ -1,86 +0,0 @@
-[![crates.io](https://img.shields.io/crates/v/multimap.svg)](https://crates.io/crates/multimap)
-[![docs.rs](https://docs.rs/multimap/badge.svg)](https://docs.rs/multimap)
-
-# Multimap implementation for Rust
-
-This is a multimap implementation for Rust. Implemented as a thin wrapper around
-`std::collections::HashMap`.
-
-## Example
-
-````rust
-extern crate multimap;
-
-use multimap::MultiMap;
-
-fn main () {
-    let mut map = MultiMap::new();
-
-    map.insert("key1", 42);
-    map.insert("key1", 1337);
-    map.insert("key2", 2332);
-
-    assert_eq!(map["key1"], 42);
-    assert_eq!(map.get("key1"), Some(&42));
-    assert_eq!(map.get_vec("key1"), Some(&vec![42, 1337]));
-}
-````
-
-## Changelog
-
-### 0.10.1
-
-* Fix docs for flat_iter #45
-* Clippy warnings
-
-### 0.10.0
-
-* Added `FromIterator<(K, Vec<V>)>` [#48](https://github.com/havarnov/multimap/pull/48).
-
-### 0.9.1
-
-* Fixes a bug where iteration would panic on empty (inner) vectors [#46](https://github.com/havarnov/multimap/issues/46).
-
-### 0.9.0
-
-* Added ```flat_iter``` and ```flat_iter_mut```
-* Fixed bug where ```get``` and ```get_mut``` could panic.
-
-### 0.8.3
-
-* `multimap!` macro fixes; allow trailing comma, naming hygiene and create with
-  enough capacity for all elements.
-
-### 0.8.2
-
-* Added ```#![forbid(unsafe_code)]```.
-
-### 0.8.1
-
-* Fixed wrong link to documentation in `Cargo.toml`.
-
-### 0.8.0
-
-* Added ```MultiMap::insert_many```.
-* Added ```MultiMap::insert_many_from_slice```.
-
-### 0.7.0
-
-* Added possibility to replace the default hasher for the underlying
-  ```HashMap```.
-* Fix build warning by removing an unnecessary ```mut```.
-
-## License
-
-Licensed under either of
- * Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or
-   https://www.apache.org/licenses/LICENSE-2.0)
- * MIT license ([LICENSE-MIT](LICENSE-MIT) or
-   https://opensource.org/licenses/MIT)
-at your option.
-
-### Contribution
-
-Unless you explicitly state otherwise, any contribution intentionally submitted
-for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
-dual licensed as above, without any additional terms or conditions.