docs: link thesis system design draft

tests/docs/test_big_doc_links.py

@@ -0,0 +1,32 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[2]
+
+
+def test_big_doc_links_case_study_and_evidence_index() -> None:
+    doc = (ROOT / "docs" / "add" / "system-design-implementation.md").read_text(
+        encoding="utf-8"
+    )
+
+    assert "examples/report_workflow" in doc
+    assert "docs/add/evidence-index.md" in doc or "evidence-index.md" in doc
+
+
+def test_project_map_links_big_doc() -> None:
+    project_map = (ROOT / "docs" / "project_map.md").read_text(encoding="utf-8")
+
+    assert "system-design-implementation.md" in project_map
+    assert "evidence-index.md" in project_map
+
+
+def test_big_doc_keeps_mcp_as_source_family() -> None:
+    doc = (ROOT / "docs" / "add" / "system-design-implementation.md").read_text(
+        encoding="utf-8"
+    )
+
+    assert "MCP" in doc
+    assert "source family" in doc
+    assert "product identity" in doc