Modularize service read paths

[yvette-carlisle]

Summary

• split progressive search storage, details, follow-up endpoints, and service entrypoints into focused modules
• split recall debug public types, trace projection, and replay artifact helpers into focused modules
• keep existing request/response shapes and endpoint method names unchanged

Validation

• cargo make check after each split segment
• final cargo make check after rebasing onto latest origin/main: 403 passed, 92 skipped

Size

• 34 files changed, 1806 insertions, 1667 deletions