Remove the legacy gRPC and gRPC-gateway server stack now that all
clients (CLI, E2E tests) have been migrated to ConnectRPC.

- Delete internal/api/v1beta1/ (65 handler files + 43 mock files)
- Delete pkg/server/interceptors/ (11 gRPC unary interceptors)
- Delete pkg/server/health/ (gRPC-only health handler)
- Remove Serve() and getGRPCMiddleware() from server.go
- Remove GRPCConfig, legacy Port, and Cors fields from config
- Remove setupNewRelic() and gRPC server startup from cmd/serve.go
- Move dedicated metrics server into ServeConnect()
- Update all E2E test configs to remove gRPC/gateway port allocations

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

The legacy gRPC-gateway server had a /ping endpoint used for liveness
checks. Add the same endpoint to the ConnectRPC server so existing
health checks and smoke tests continue to work.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Remove grpc/go, grpc-ecosystem/gateway, and grpc-ecosystem/openapiv2
plugins from buf.gen.yaml since the gRPC server has been removed.

- Delete generated *_grpc.pb.go and *.pb.gw.go stubs
- Delete generated apidocs.swagger.yaml
- Remove grpc-gateway managed disable (no longer needed)

Only protobuf messages, validate, and connectrpc plugins remain.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

The OIDC callback test was using a raw HTTP GET to the gRPC-gateway
REST endpoint /v1beta1/auth/callback. Convert it to use the ConnectRPC
client directly, matching the pattern already used by the mailotp test.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

whoAbhishekSah added a commit that referenced this pull request

- Remove `port` and `grpc` section from sample config
- Update callback_urls to use ConnectRPC endpoint
- Update docker-compose ports: replace REST/gRPC with connect (8002) and metrics (9000)
- go mod tidy: remove gorilla/handlers, oklog/run; demote golang/protobuf and otelgrpc to indirect

Follow-up to #1404 which removed all gRPC server code.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

whoAbhishekSah added a commit that referenced this pull request

- Remove `port` and `grpc` section from sample config
- Update callback_urls to use ConnectRPC endpoint
- Update docker-compose ports: replace REST/gRPC with connect (8002) and metrics (9000)
- go mod tidy: remove gorilla/handlers, oklog/run; demote golang/protobuf and otelgrpc to indirect

Follow-up to #1404 which removed all gRPC server code.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

whoAbhishekSah added a commit that referenced this pull request

- Remove `port` and `grpc` section from sample config
- Update callback_urls to use ConnectRPC endpoint
- Update docker-compose ports: replace REST/gRPC with connect (8002) and metrics (9000)
- go mod tidy: remove gorilla/handlers, oklog/run; demote golang/protobuf and otelgrpc to indirect

Follow-up to #1404 which removed all gRPC server code.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

whoAbhishekSah added a commit that referenced this pull request

- Remove `port` and `grpc` section from sample config
- Update callback_urls to use ConnectRPC endpoint
- Update docker-compose ports: replace REST/gRPC with connect (8002) and metrics (9000)
- go mod tidy: remove gorilla/handlers, oklog/run; demote golang/protobuf and otelgrpc to indirect

Follow-up to #1404 which removed all gRPC server code.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

This was referenced