Replace JoeAppEngine tags with TestChildObject tags (TestBool, TestInt, TestFloat,
TestDouble, TestString, TestDateTime, and array variants) in Phase 4 and Phase 7
plans. These tags cover all TypedValue oneof cases for comprehensive v2 testing.
Design doc covers architecture, v2 protocol (TypedValue/QualityCode), COM threading
model, session lifecycle, subscription semantics, error model, and guardrails.
Implementation plans are detailed enough for autonomous Claude Code execution.
Verified all dev tooling on windev (Grpc.Tools, protobuf-net.Grpc, Polly v8, xUnit).
