fix(a365): preserve scope attribute precedence

[Nikhil Navakiran (nikhilNava)]

Summary

• track attributes actually populated by manual A365 scope builders
• prevent recordAttributes() from overwriting builder-owned values
• continue allowing absent known attributes and last-write-wins custom attributes

Validation

• targeted TDD: 72 tests passed
• npm run build
• npm run format
• npm run lint (warnings only)
• npm run test:unit (1096 passed, 5 todo)
• npm run docs (existing warnings only)
• git diff --check

Parity with microsoft/opentelemetry-distro-dotnet#107. ETW logger changes are out of scope.