Context

Part of kcenon/common_system#685 (Wave 2, P1).

Acceptance Criteria

• remove deprecated include/container forwarders + root container.h shim per v1.2.0 plan
• prune unnecessary target aliases
• dedup utilities/conversion vs utilities/core convert_string.h
• fold grpc/ build into the default preset matrix or a dedicated CI job
• sync Doxyfile version (0.1.0 -> 1.0.0)
• document samples/ vs examples/ role boundary

Notes

grpc CI integration touches .github/workflows/ -> requires workflow token scope.

Derived from the 2026-05-30 multi-agent cross-system level-matching analysis (workflow wf_0a968699-e07). Reference systems: documentation=common_system, code-structure=monitoring_system, tests/examples=container_system.