Reorganize documentation into canonical repository layout

Adopt CoulombSocial/HelixForge/MarkiTect documentation structure:
- research/260608-yawex-prior-art/ — yawex exploration and sources
- demand/ — inbound NetKingdom integration requirements
- spec/ — PRD, TSD, UseCaseCatalog, ArchitectureBlueprint scaffolds
- docs/ — stakeholder documentation and repository-layout guide
- wiki/, issues/, history/ — scaffolded directories

Add SCOPE.md and AGENTS.md. Update workplan paths and README.

research/README.md

@@ -0,0 +1,13 @@
+# research/
+
+Exploration results for the problem and solution space.
+
+Each exploration uses a `yymmdd-` prefix on the markdown file or subdirectory
+when multiple files or sources are involved. Findings here inform `spec/` and
+`SCOPE.md`; they do not directly authorize implementation until promoted.
+
+## Active Explorations
+
+| Date | Path | Summary |
+|------|------|---------|
+| 2026-06-08 | `260608-yawex-prior-art/` | yawex 0.7.4 Perl wiki prior art; federation design seeds |