test(conversations): verrouille le schéma NDJSON exact de l'app (schema:1)

Test dédié : _meta en 1ʳᵉ ligne skippée, tours à 10 clés (id int→str, role enum
PATIENT/KAZEIA, ttft_ms/total_ms/voice_used/model_used en null explicite acceptés).
Garantit qu'une dérive de schéma ne passe pas en silence.

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

tests/test_conversations.py

@@ -68,6 +68,26 @@ def test_collect_empty_still_purges(tmp_path):
     assert r["exported"] == 0 and r["archived"] == 0 and r["purged"] is True
 
 
+def test_collect_matches_app_ndjson_schema(tmp_path):
+    # Schéma EXACT figé par l'app (KazeiaTelemetryProvider.conversationsExport, schema:1) :
+    # _meta en 1ʳᵉ ligne + tours à 10 clés, id=int, role enum, 4 champs nullable en `null`.
+    s = _store(tmp_path)
+    nd = ('{"_meta":{"schema":1,"exported_at":1782920549886,"count":2,"filter":{}}}\n'
+          '{"id":123,"profile_id":"p_ec7aba19","session_id":"s_1","timestamp":1782920500000,'
+          '"role":"PATIENT","text":"j\'ai mal : dormi","ttft_ms":210,"total_ms":1840,'
+          '"voice_used":"richard","model_used":"qwen3.5-4b"}\n'
+          '{"id":124,"profile_id":"p_ec7aba19","session_id":"s_1","timestamp":1782920501000,'
+          '"role":"KAZEIA","text":"tu te sens fatiguée ?","ttft_ms":null,"total_ms":null,'
+          '"voice_used":null,"model_used":null}\n')
+    r = csvc.collect(_ConvAdb(nd, 2), s, "D1", now=NOW)
+    assert r["exported"] == 2 and r["archived"] == 2 and r["purged"] is True
+    turns = s.session_turns("D1", "s_1")
+    assert [t["turn_id"] for t in turns] == ["123", "124"]       # id int → clé str, pas de collision
+    assert [t["role"] for t in turns] == ["PATIENT", "KAZEIA"]
+    assert turns[1]["ttft_ms"] is None and turns[1]["voice_used"] is None   # nullables acceptés, pas de crash
+    assert turns[0]["voice_used"] == "richard"
+
+
 def test_sessions_and_purge(tmp_path):
     s = _store(tmp_path)
     s.archive_turns("D1", [