feat(auth): replace internal auth with JWT token service

- Replace InternalAuthService with TokenService using JWT tokens
- Add support for token issuance, refresh, verification and revocation
- Implement automatic signing key rotation with Redis storage
- Add database migration checks for indexes and foreign key constraints
- Update gRPC endpoints to use token-based authentication
- Remove deprecated API key based authentication system
- Add JSON Web Token support with HMAC-SHA256 signing
- Implement refresh token handling with automatic rotation
- Add token revocation by JTI and user ID
- Update build configuration to include core proto files
- Migrate database schema to handle token-based authentication
- Add comprehensive token validation and verification logic

pb/core.rs

@@ -0,0 +1,5 @@
+// Generated from proto/core/*.proto (package appks.core.v1)
+// Compiled via tonic-build in build.rs using OUT_DIR + include!
+// Build server = true, build client = true (appks serves TokenService, imks consumes it).
+
+include!(concat!(env!("OUT_DIR"), "/appks.core.v1.rs"));