0.2.3

Enhance OIDC claims model and tests

Bump package version to 0.2.3. Add Authentik-specific AKProxy and AKProxyUserAttributes Pydantic models and greatly expand ValidatedOIDCClaims (extra fields, Field metadata, and model_config extra="allow") to cover standard OIDC claims, profile/email/authorization claims, and Authentik extensions (entitlements, roles, groups, ak_proxy). Update OIDCTokenValidator to resolve a matching JWKS entry and construct a PyJWK key for verification, raising PyJWKSetError if no matching kid is found. Replace the prior superficial/mocked test with realistic RSA-signed token tests and fixtures: generate keypairs, build JWKS, sign tokens, and add tests for valid tokens, expired tokens, wrong audience/issuer, tampered signature, unknown kid, and tokens signed with the wrong key — improving coverage and robustness.