Add type-location map and DRY measurement docs
Added a "Type-Location Map" to the plugin README for quick type lookup. Updated MEASUREMENT.md to reference canonical definitions in DOMAIN_MODEL.md for shared measurement logic, reducing duplication. Clarified pallet weighing workflow and fixed the client app doc path. Minor formatting and clarity improvements.
- Restructured documentation: added `docs/README.md` to each sub-project, moved LOGGING and SIGNALR docs into dedicated subfolders with their own `README.md`.
- Updated all cross-references to use new topic folder paths and canonical AyCode.Core doc locations.
- Updated `.csproj` files to auto-include all Markdown docs and project-level `README.md` files.
- Removed obsolete single-file docs, replaced with structured content in topic folders.
- Enforced AI Agent Protocol: session setup, output prefix, no-re-read, and mandatory `docs-check` skill after code changes.
- Added domain-critical reminders and navigation guidance to relevant `README.md` files.
Loretta