chore: docs/ prose-only gate + drop validate.py legacy fallback

.github/workflows/ci.yml

@@ -31,3 +31,6 @@ jobs:
 
       - name: Manifest drift gate (Phase 0 / Track C)
         run: make check-manifest
+
+      - name: docs/ prose-only gate
+        run: make check-docs-prose

Makefile

@@ -1,6 +1,6 @@
 .PHONY: install hooks test test-lf watch lint format mypy cov check push pull \
         sources sources-anno sources-ydb serve-anno extract reconcile validate all clean \
-        integrated check-manifest
+        integrated check-manifest check-docs-prose
 
 PYTHON     := .venv/bin/python
 PYTEST     := .venv/bin/pytest
@@ -117,3 +117,21 @@ integrated:
 # every `exposes.*` payload still exists on disk and (for .json) parses.
 check-manifest: integrated
 	$(PYTHON) tools/check-repo-meta.py dist/repo.meta.json
+
+# Guardrail: docs/ holds only human-readable prose. Non-prose artifacts
+# (generated data, JSON/TSV output, copy-paste examples, scaffolding
+# templates) belong under dist/, examples/, templates/, or a top-level
+# domain-specific directory — not docs/.
+check-docs-prose:
+	@if [ ! -d docs ]; then echo "check-docs-prose: no docs/ directory ✓"; exit 0; fi; \
+	violations=$$(find docs -type f \
+	    ! -name '*.md' ! -name '*.markdown' \
+	    ! -name '*.png' ! -name '*.jpg' ! -name '*.jpeg' \
+	    ! -name '*.gif' ! -name '*.svg' ! -name '*.webp' \
+	    ! -name '.gitkeep'); \
+	if [ -n "$$violations" ]; then \
+	  echo "ERROR: non-prose files under docs/ — move to dist/, examples/, templates/, or a top-level domain dir:" >&2; \
+	  echo "$$violations" >&2; \
+	  exit 1; \
+	fi; \
+	echo "check-docs-prose: docs/ is prose-only ✓"

src/m_standard/tools/validate.py

@@ -34,19 +34,10 @@
 def _integrated_dir(project_root: Path) -> Path:
     """Resolve the integrated/ directory location.
 
-    The canonical layout has `integrated/` at the repo root, alongside
-    `per-source/`, `schemas/`, `sources/`, and `src/`. The repo briefly
-    held it at `docs/integrated/` (3bfb947 .. its reversion); the
-    fallback is kept for one release cycle so a stale checkout still
-    validates.
+    `integrated/` lives at the repo root, alongside `per-source/`,
+    `schemas/`, `sources/`, and `src/`.
     """
-    canonical = project_root / "integrated"
-    if canonical.is_dir():
-        return canonical
-    legacy = project_root / "docs" / "integrated"
-    if legacy.is_dir():
-        return legacy
-    return canonical
+    return project_root / "integrated"
 
 
 # Names that are ALWAYS tracked under sources/<src>/ regardless of