diff --git a/tests/test_dp_finalizer_ext.py b/tests/test_dp_finalizer_ext.py
new file mode 100644
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+++ b/tests/test_dp_finalizer_ext.py
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+"""Tests étendus pour src/medical/dp_finalizer.py.
+
+Couvre les cas non couverts dans test_dp_finalizer.py :
+- R6 — Z-code non whitelisté remplacé par DAS
+- Fonctions internes (_family3, _code_in_candidates, _has_strong_evidence)
+- finalize_dp avec source Trackare détectée par evidence/reason
+- Cas limites : codes None, candidats vides, Z whitelistés en R6
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from src.config import DossierMedical, DPSelection, DPCandidate, Diagnostic, Sejour
+from src.medical.dp_finalizer import (
+    finalize_dp,
+    decide_dp_final,
+    _family3,
+    _code_in_candidates,
+    _has_strong_evidence,
+    _apply_r5,
+    _make_selection,
+)
+
+
+# ── Helpers ────────────────────────────────────────────────────────────
+
+
+def _sel(
+    code: str | None = None,
+    term: str = "",
+    verdict: str = "REVIEW",
+    confidence: str = "medium",
+    evidence: list[str] | None = None,
+    reason: str = "",
+    candidates: list[DPCandidate] | None = None,
+) -> DPSelection:
+    return DPSelection(
+        chosen_code=code,
+        chosen_term=term or (code or ""),
+        verdict=verdict,
+        confidence=confidence,
+        evidence=evidence or [],
+        reason=reason,
+        candidates=candidates or [],
+    )
+
+
+def _cand(code: str, term: str = "", score: float = 0.0) -> DPCandidate:
+    return DPCandidate(index=0, term=term or code, code=code, score=score)
+
+
+def _dossier(
+    doc_type: str = "crh",
+    dp_selection: DPSelection | None = None,
+    das: list[Diagnostic] | None = None,
+) -> DossierMedical:
+    return DossierMedical(
+        document_type=doc_type,
+        sejour=Sejour(),
+        dp_selection=dp_selection,
+        diagnostics_associes=das or [],
+    )
+
+
+# ===================================================================
+# Fonctions internes
+# ===================================================================
+
+
+class TestFamily3:
+    @pytest.mark.parametrize("code,expected", [
+        ("K81.0", "K81"),
+        ("K81", "K81"),
+        ("I26.9", "I26"),
+        ("Z51.1", "Z51"),
+        (None, ""),
+        ("", ""),
+    ])
+    def test_extraction(self, code, expected):
+        assert _family3(code) == expected
+
+
+class TestCodeInCandidates:
+    def test_exact_match(self):
+        sel = _sel(candidates=[_cand("I26.9"), _cand("K85.1")])
+        assert _code_in_candidates("I26.9", sel) is True
+
+    def test_family3_match(self):
+        sel = _sel(candidates=[_cand("I26.9")])
+        assert _code_in_candidates("I26.0", sel) is True  # same family
+
+    def test_no_match(self):
+        sel = _sel(candidates=[_cand("I26.9")])
+        assert _code_in_candidates("K85.1", sel) is False
+
+    def test_none_code(self):
+        sel = _sel(candidates=[_cand("I26.9")])
+        assert _code_in_candidates(None, sel) is False
+
+    def test_empty_candidates(self):
+        sel = _sel(candidates=[])
+        assert _code_in_candidates("I26.9", sel) is False
+
+
+class TestHasStrongEvidence:
+    def test_no_evidence(self):
+        sel = _sel(evidence=[])
+        assert _has_strong_evidence(sel) is False
+
+    def test_only_trackare_source(self):
+        """'Source: Trackare' seul n'est pas une preuve forte."""
+        sel = _sel(evidence=["Source: Trackare (codage établissement)"])
+        assert _has_strong_evidence(sel) is False
+
+    def test_strong_evidence(self):
+        sel = _sel(evidence=["Diagnostic de sortie: «Embolie pulmonaire»"])
+        assert _has_strong_evidence(sel) is True
+
+    def test_mixed_evidence(self):
+        sel = _sel(evidence=[
+            "Source: Trackare (codage établissement)",
+            "Conclusion CRH: «Pancréatite biliaire»",
+        ])
+        assert _has_strong_evidence(sel) is True
+
+
+class TestMakeSelection:
+    def test_preserves_source_candidates(self):
+        source = _sel(candidates=[_cand("I26.9", "EP", 5.0)])
+        result = _make_selection(
+            code="I26.9", term="EP", verdict="CONFIRMED",
+            confidence="high", evidence=[], reason="test",
+            source_sel=source,
+        )
+        assert len(result.candidates) == 1
+        assert result.candidates[0].code == "I26.9"
+
+    def test_no_source(self):
+        result = _make_selection(
+            code="I26.9", term="EP", verdict="CONFIRMED",
+            confidence="high", evidence=[], reason="test",
+        )
+        assert result.candidates == []
+        assert result.debug_scores is None
+
+
+# ===================================================================
+# R5 — _apply_r5 (direct call)
+# ===================================================================
+
+
+class TestApplyR5Direct:
+    def test_z_code_non_whitelisted_forced_review(self):
+        dp = _sel(code="Z95.5", verdict="CONFIRMED", confidence="high", evidence=[])
+        dp, flags, alertes = _apply_r5(dp, None, allow_symptom_dp=False)
+        assert dp.verdict == "REVIEW"
+        assert flags.get("z_code_dp_review") is True
+
+    def test_z_code_whitelisted_untouched(self):
+        dp = _sel(code="Z51.1", verdict="CONFIRMED", confidence="high", evidence=[])
+        dp, flags, alertes = _apply_r5(dp, None, allow_symptom_dp=False)
+        assert dp.verdict == "CONFIRMED"
+        assert "z_code_dp_review" not in flags
+
+    def test_r_code_with_non_r_candidate(self):
+        crh = _sel(candidates=[_cand("R06.0"), _cand("J18.9")])
+        dp = _sel(code="R06.0", verdict="CONFIRMED", confidence="high", evidence=[])
+        dp, flags, alertes = _apply_r5(dp, crh, allow_symptom_dp=False)
+        assert dp.verdict == "REVIEW"
+        assert flags.get("r_code_dp_with_non_r_candidate") is True
+
+    def test_r_code_allowed_by_flag(self):
+        crh = _sel(candidates=[_cand("R06.0"), _cand("J18.9")])
+        dp = _sel(code="R06.0", verdict="CONFIRMED", confidence="high", evidence=[])
+        dp, flags, alertes = _apply_r5(dp, crh, allow_symptom_dp=True)
+        assert dp.verdict == "CONFIRMED"
+
+    def test_review_dp_not_changed(self):
+        """R5 ne touche que les CONFIRMED."""
+        dp = _sel(code="Z95.5", verdict="REVIEW", confidence="medium", evidence=[])
+        dp, flags, alertes = _apply_r5(dp, None, allow_symptom_dp=False)
+        assert dp.verdict == "REVIEW"
+        assert "z_code_dp_review" not in flags  # pas de flag car déjà REVIEW
+
+
+# ===================================================================
+# R6 — Z-code remplacé par DAS (via finalize_dp)
+# ===================================================================
+
+
+class TestR6ZcodeReplacedByDas:
+    def test_z_code_replaced_by_das(self):
+        """Z-code non whitelisté en DP → DAS high/medium non-R non-Z promu."""
+        sel = _sel(
+            code="Z96.6",  # non whitelisté
+            verdict="CONFIRMED",
+            evidence=["Source: Trackare (codage établissement)"],
+            reason="DP Trackare",
+        )
+        das = [
+            Diagnostic(texte="Pancréatite", cim10_suggestion="K85.9", cim10_confidence="high"),
+        ]
+        d = _dossier(doc_type="trackare", dp_selection=sel, das=das)
+        finalize_dp(d)
+
+        assert d.dp_final is not None
+        assert d.dp_final.chosen_code == "K85.9"
+        assert d.quality_flags.get("z_code_replaced_by_das") is True
+        assert any("K85.9" in a for a in d.alertes_codage)
+
+    def test_z_code_whitelisted_not_replaced(self):
+        """Z-code whitelisté en DP → pas de remplacement."""
+        sel = _sel(
+            code="Z51.1",  # whitelisté
+            verdict="CONFIRMED",
+            evidence=["Source: Trackare (codage établissement)"],
+            reason="DP Trackare",
+        )
+        das = [
+            Diagnostic(texte="Pancréatite", cim10_suggestion="K85.9", cim10_confidence="high"),
+        ]
+        d = _dossier(doc_type="trackare", dp_selection=sel, das=das)
+        finalize_dp(d)
+
+        assert d.dp_final.chosen_code == "Z51.1"
+        assert "z_code_replaced_by_das" not in d.quality_flags
+
+    def test_z_code_no_eligible_das(self):
+        """Z-code non whitelisté mais aucun DAS éligible → pas de remplacement."""
+        sel = _sel(
+            code="Z96.6",
+            verdict="CONFIRMED",
+            evidence=["Source: Trackare (codage établissement)"],
+            reason="DP Trackare",
+        )
+        das = [
+            Diagnostic(texte="Symptôme R", cim10_suggestion="R10.4", cim10_confidence="high"),
+            Diagnostic(texte="Z-code", cim10_suggestion="Z87.1", cim10_confidence="low"),
+        ]
+        d = _dossier(doc_type="trackare", dp_selection=sel, das=das)
+        finalize_dp(d)
+
+        # R10.4 est R-code, Z87.1 est Z-code → aucun éligible
+        assert "z_code_replaced_by_das" not in d.quality_flags
+
+
+# ===================================================================
+# finalize_dp — détection source Trackare
+# ===================================================================
+
+
+class TestFinalizeDpSourceDetection:
+    def test_trackare_detected_by_document_type(self):
+        sel = _sel(code="K81.0", verdict="CONFIRMED", evidence=[], reason="CRH DP")
+        d = _dossier(doc_type="trackare", dp_selection=sel)
+        finalize_dp(d)
+        assert d.dp_trackare is not None
+
+    def test_trackare_detected_by_reason(self):
+        sel = _sel(code="K81.0", verdict="CONFIRMED", evidence=[],
+                   reason="DP Trackare — source d'autorité")
+        d = _dossier(doc_type="crh", dp_selection=sel)
+        finalize_dp(d)
+        assert d.dp_trackare is not None
+
+    def test_trackare_detected_by_evidence(self):
+        sel = _sel(code="K81.0", verdict="CONFIRMED",
+                   evidence=["Source: Trackare (codage établissement)"],
+                   reason="DP")
+        d = _dossier(doc_type="crh", dp_selection=sel)
+        finalize_dp(d)
+        assert d.dp_trackare is not None
+
+    def test_crh_only_when_no_trackare_signal(self):
+        sel = _sel(code="K81.0", verdict="CONFIRMED",
+                   evidence=["Diagnostic de sortie CRH"],
+                   reason="CRH CONFIRMED")
+        d = _dossier(doc_type="crh", dp_selection=sel)
+        finalize_dp(d)
+        assert d.dp_trackare is None
+        assert d.dp_crh_only is not None
+
+
+# ===================================================================
+# finalize_dp — pas de dp_selection
+# ===================================================================
+
+
+class TestFinalizeDpNoSelection:
+    def test_no_dp_selection(self):
+        """Dossier sans dp_selection → REVIEW, flag no_dp_source."""
+        d = _dossier(doc_type="crh")
+        finalize_dp(d)
+        assert d.dp_final is not None
+        assert d.dp_final.verdict == "REVIEW"
+        assert d.quality_flags.get("no_dp_source") is True
+
+
+# ===================================================================
+# decide_dp_final — edge cases
+# ===================================================================
+
+
+class TestDecideDpFinalEdgeCases:
+    def test_trackare_z_code_whitelisted(self):
+        """Z03 (whitelisté) en Trackare-only → CONFIRMED."""
+        trackare = _sel(code="Z03.8", verdict="CONFIRMED",
+                        evidence=["Source: Trackare"])
+        dp, flags, _ = decide_dp_final(trackare, None)
+        # Z03 is whitelisted
+        assert dp.verdict == "CONFIRMED"
+
+    def test_trackare_empty_evidence_gets_default(self):
+        """Trackare-only sans evidence → evidence par défaut ajoutée."""
+        trackare = _sel(code="K81.0", verdict="CONFIRMED", evidence=[])
+        dp, flags, _ = decide_dp_final(trackare, None)
+        assert any("Trackare" in e for e in dp.evidence)
+
+    def test_both_sources_trackare_review_from_selector(self):
+        """Si dp_selector a déjà mis REVIEW, le finalizer le respecte."""
+        trackare = _sel(code="K81.0", verdict="REVIEW",
+                        evidence=["Source: Trackare"])
+        crh = _sel(code="K81.0", verdict="REVIEW",
+                   evidence=["Diagnostic CRH"],
+                   candidates=[_cand("K81.0")])
+        dp, flags, _ = decide_dp_final(trackare, crh)
+        # R2 corrobore → CONFIRMED
+        assert dp.verdict == "CONFIRMED"
+        assert flags.get("trackare_confirmed_by_crh") is True
+
+    def test_code_none_handling(self):
+        """Trackare avec code None → pas de crash."""
+        trackare = _sel(code=None, verdict="REVIEW", evidence=["Source: Trackare"])
+        crh = _sel(code="K81.0", verdict="CONFIRMED",
+                   evidence=["Diagnostic de sortie CRH"])
+        dp, flags, _ = decide_dp_final(trackare, crh)
+        # Code None ne commence pas par R, ne commence pas par Z
+        # Il ne matche pas CRH → R4 ambigu
+        assert dp is not None