Batch modularize validation and acceptance helpers

[yvette-carlisle]

Summary

• split competitor strength profile assertions into focused modules
• split docs put/search validation tests into grouped submodules and support helpers
• split structured field retrieval and trace admin observability acceptance helpers behind normal Rust modules

Validation

• RUSTC=/run/current-system/sw/bin/rustc cargo make fmt-rust && RUSTC=/run/current-system/sw/bin/rustc cargo make check
• final local run: 403 tests passed, 92 skipped

Diff size

• 25 files changed, 2290 insertions, 2177 deletions