feat(eda): render de models en markdown + PDF DB-level para profile_database (H4,H9)

- H4: render_eda_markdown anade seccion Modelos (PCA/KMeans/normalidad/outliers);
  render_eda_pdf formatea models/series/caveats como tablas (no str(dict) crudo)
- H9: profile_database gana flag emit_pdf -> PDF movil DB-level (resumen tablas +
  join graph) via render_eda_pdf_relational; clave report_pdf_path
- aditivos y retrocompatibles (flags default False). 38 tests verdes

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

python/functions/pipelines/profile_database_test.py

@@ -165,3 +165,36 @@ def test_profile_database_writes_report(tmp_path):
     assert "# EDA base —" in md
     assert "## Relaciones inter-tabla" in md
     assert "```mermaid" in md
+
+
+def test_profile_database_emit_pdf(tmp_path):
+    # H9: con emit_pdf=True, profile_database genera un PDF DB-level (>0 bytes,
+    # cabecera %PDF) además del markdown + JSON.
+    db_path = os.path.join(str(tmp_path), "shop3.duckdb")
+    _build_related_db(db_path)
+    report_dir = os.path.join(str(tmp_path), "reports")
+
+    res = profile_database(
+        db_path, report_dir=report_dir, write_report=True, emit_pdf=True
+    )
+
+    assert res["status"] == "ok", res
+    pdf = res.get("report_pdf_path")
+    assert pdf is not None
+    assert os.path.exists(pdf)
+    assert os.path.getsize(pdf) > 0
+    with open(pdf, "rb") as fh:
+        assert fh.read(4) == b"%PDF"
+
+
+def test_profile_database_emit_pdf_false_retrocompat(tmp_path):
+    # Edge: emit_pdf=False (default) se comporta como antes — no genera PDF y
+    # report_pdf_path es None.
+    db_path = os.path.join(str(tmp_path), "shop4.duckdb")
+    _build_related_db(db_path)
+    report_dir = os.path.join(str(tmp_path), "reports")
+
+    res = profile_database(db_path, report_dir=report_dir, write_report=True)
+
+    assert res["status"] == "ok", res
+    assert res.get("report_pdf_path") is None