gRPC C++ 1.84

Apply the C++23 prompt first. These rules cover gRPC Core/C++ on the 1.84 line, built with a consistently configured, supported C++23 toolchain.

Build and generated code

• Keep the deployed gRPC line inside the project's rolling support window: the current stable line and the line immediately before it receive ordinary bug and security fixes. Check the release index and Core advisories when packaging statically linked binaries, since a package scanner may not identify the embedded copy.
• Resolve the actual Bazel or CMake dependency graph, including gRPC_<depname>_PROVIDER choices and overrides. Generate Protobuf C++ code with the exact Protobuf runtime linked into the process, use the grpc_cpp_plugin from the same gRPC release as the linked runtime, and rebuild generated and dependent objects together. Wire compatibility does not promise a stable C++ ABI.
• Keep the message_size_refactoring, ph2_perf_01, and header_data_frame Core experiments active. Remove deployment GRPC_EXPERIMENTS overrides that disable them; they carry transport memory exhaustion protections, including decompression bounds. Preserve those protections in any downstream Core build.

Secure channels and peer identity

• Give every network listener and channel an authenticated transport with SslServerCredentials and SslCredentials, or another reviewed authenticated transport. Keep InsecureServerCredentials and InsecureChannelCredentials inside an independently protected local boundary or tests. Bind the intended DNS identity to certificate verification; do not turn off