feat: add external authorization service (authzd) with JWT authentication

- Add new authzd gRPC service implementing Envoy's external authorization API
- Integrate JWT authentication filter in Envoy configuration with claim extraction
- Update middleware to support both cookie-based and header-based user authentication
- Add comprehensive test coverage for authorization service and server
- Configure proper service orchestration with authzd, sparkled, and Envoy
- Update build system and Docker configuration for multi-service deployment
- Add grpcurl tool for gRPC service debugging and testing

This enables fine-grained authorization control through Envoy's ext_authz filter
while maintaining backward compatibility with existing cookie-based authentication.

1 files changed, 2 insertions, 0 deletions

diff --git a/vendor/cel.dev/expr/.gitignore b/vendor/cel.dev/expr/.gitignore
new file mode 100644
index 0000000..0d4fed2
--- /dev/null
+++ b/vendor/cel.dev/expr/.gitignore
@@ -0,0 +1,2 @@
+bazel-*
+MODULE.bazel.lock