Consolidate mw/log design documentation into docs/

### What

PlantUML design diagrams for mw::log and DataRouter are spread across score/mw/log/design/, score/mw/log/detail/ (logging repo), and score/mw/log/design/ (baselibs repo). None are linked to the Sphinx build, so they are invisible in published docs.

Move all mw/log-relevant diagrams into docs/components/datarouter/detailed_design/ and docs/components/mw/log/detailed_design/, add RST scaffold files, and update component toctrees. Generic baselibs utility diagrams stay in baselibs.

### Acceptance Criteria (DoD)

All MW/log-related PUML diagrams are now in the docs/components/ folders. They are included in the Sphinx documentation using RST files, and bazel run //:docs_check completes without any warnings.

### How

_No response_