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, 20 insertions, 0 deletions

diff --git a/vendor/github.com/xlgmokha/x/pkg/context/key.go b/vendor/github.com/xlgmokha/x/pkg/context/key.go
new file mode 100644
index 00000000..80ca7bd2
--- /dev/null
+++ b/vendor/github.com/xlgmokha/x/pkg/context/key.go
@@ -0,0 +1,20 @@
+package context
+
+import (
+	"context"
+
+	"github.com/xlgmokha/x/pkg/x"
+)
+
+type Key[T any] string
+
+func (self Key[T]) With(ctx context.Context, value T) context.Context {
+	return context.WithValue(ctx, self, value)
+}
+
+func (self Key[T]) From(ctx context.Context) T {
+	if value := ctx.Value(self); value != nil {
+		return value.(T)
+	}
+	return x.Zero[T]()
+}