Tidy the repository: remove docs/research and bench, fix references

README.md

@@ -8,7 +8,7 @@ methylation control QC).
 
 - **SIMURGARRAY_MASTER_PLAN.md** — architecture, algorithms, roadmap
 - **SIMURGARRAY_FUNCTIONAL_SPEC.md** — 416 itemised requirements (CLI, inputs, outputs, QC, CN, PGx, methylation, edge cases)
-- `docs/validation/` — per-phase validation reports · `docs/known_unknowns.md` — findings log · `docs/research/` — background
+- `docs/validation/` — per-phase validation reports · `docs/known_unknowns.md` — findings log
 - `branding/` — logo, icons, templates and the brand guide · `blog/` — five posts about the project
 
 ## Status