feat: implement OIDC authentication for admin users (#316)

## Summary

This PR implements OIDC authentication support for admin users,
specifically configured for Google Cloud Identity. The implementation
includes:

- Configurable OIDC authentication endpoints and validation
- Google Cloud Identity integration for admin access
- JWT token validation and user session management
- Deployment configuration updates for OIDC provider settings

Fixes #283

go.mod

@@ -4,6 +4,7 @@ go 1.24.0
 
 require (
 	github.com/caarlos0/env/v11 v11.3.1
+	github.com/coreos/go-oidc/v3 v3.15.0
 	github.com/danielgtaylor/huma/v2 v2.34.1
 	github.com/golang-jwt/jwt/v5 v5.3.0
 	github.com/google/uuid v1.6.0
@@ -17,12 +18,15 @@ require (
 	go.opentelemetry.io/otel/metric v1.37.0
 	go.opentelemetry.io/otel/sdk v1.37.0
 	go.opentelemetry.io/otel/sdk/metric v1.37.0
+	golang.org/x/mod v0.27.0
+	golang.org/x/oauth2 v0.30.0
 )
 
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/go-jose/go-jose/v4 v4.0.5 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/grafana/regexp v0.0.0-20240518133315-a468a5bfb3bc // indirect
@@ -38,7 +42,6 @@ require (
 	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
 	go.opentelemetry.io/otel/trace v1.37.0 // indirect
 	golang.org/x/crypto v0.41.0 // indirect
-	golang.org/x/mod v0.27.0 // indirect
 	golang.org/x/sys v0.35.0 // indirect
 	golang.org/x/text v0.28.0 // indirect
 	google.golang.org/protobuf v1.36.6 // indirect