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, 44 deletions

diff --git a/vendor/urlencoding/README.md b/vendor/urlencoding/README.md
deleted file mode 100644
index 3134060f..00000000
--- a/vendor/urlencoding/README.md
+++ /dev/null
@@ -1,44 +0,0 @@
-# urlencoding
-
-[![Latest Version](https://img.shields.io/crates/v/urlencoding.svg)](https://lib.rs/crates/urlencoding)
-
-A tiny Rust library for doing URL percentage encoding and decoding. It percent-encodes everything except alphanumerics and `-`, `_`, `.`, `~`.
-
-When decoding `+` is not treated as a space. Error recovery from incomplete percent-escapes follows the [WHATWG URL standard](https://url.spec.whatwg.org/).
-
-## Usage
-
-To encode a string, do the following:
-
-```rust
-use urlencoding::encode;
-
-let encoded = encode("This string will be URL encoded.");
-println!("{}", encoded);
-// This%20string%20will%20be%20URL%20encoded.
-```
-
-To decode a string, it's only slightly different:
-
-```rust
-use urlencoding::decode;
-
-let decoded = decode("%F0%9F%91%BE%20Exterminate%21")?;
-println!("{}", decoded);
-// 👾 Exterminate!
-```
-
-To decode allowing arbitrary bytes and invalid UTF-8:
-
-```rust
-use urlencoding::decode_binary;
-
-let binary = decode_binary(b"%F1%F2%F3%C0%C1%C2");
-let decoded = String::from_utf8_lossy(&binary);
-```
-
-This library returns [`Cow`](https://doc.rust-lang.org/stable/std/borrow/enum.Cow.html) to avoid allocating when decoding/encoding is not needed. Call `.into_owned()` on the `Cow` to get a `Vec` or `String`.
-
-## License
-
-This project is licensed under the MIT license. For more information see the `LICENSE` file.