feat(agent): v4.10.1 - config LLM dans l'UI (sélecteur provider/modèle, config runtime, admin + test connexion)

- Panneau agent : selects provider/modèles connus persistés par conversation
  (colonnes agent_conversations.provider/model, migration idempotente)
- GET /api/agent/providers enrichi (liste providers + modèles + requires_key)
- PATCH /api/agent/providers (admin) : config runtime DB-backed (table llm_config)
- POST /api/agent/providers/test : test connexion via LLMClient.ping() sans fallback mock
- Settings > Admin > Agent & IA : provider, modèle, clé API, URL API, save + test
- VERSION -> 4.10.1, CHANGELOG + ROADMAP mis à jour, 232 tests verts

tests/test_agent.py

@@ -317,6 +317,98 @@ def test_router_tools_and_providers(client):
     prov = client.get("/api/agent/providers").json()
     assert prov["provider"] == "offline"
     assert prov["available"] is False
+    assert "providers" in prov
+
+
+def test_router_providers_enriched(client):
+    prov = client.get("/api/agent/providers").json()
+    assert "providers" in prov
+    ids = [p["id"] for p in prov["providers"]]
+    for expected in ("openai", "anthropic", "google", "ollama", "offline"):
+        assert expected in ids
+    openai = next(p for p in prov["providers"] if p["id"] == "openai")
+    assert openai["default_model"] == "gpt-4o"
+    assert openai["models"]
+    assert openai["requires_key"] is True
+    # offline requires no key and exposes no models
+    offline = next(p for p in prov["providers"] if p["id"] == "offline")
+    assert offline["requires_key"] is False
+
+
+def test_router_patch_providers_updates_config(client):
+    from app.auth.session import SessionManager
+    from app.db import get_conn
+
+    with get_conn() as conn:
+        admin = conn.execute("SELECT * FROM users WHERE login='admin'").fetchone()
+        sess = SessionManager.create_session(dict(admin))
+
+    client.cookies.set("flowdeck_session", sess)
+    r = client.patch("/api/agent/providers",
+                     json={"provider": "openai", "model": "gpt-4o-mini",
+                           "api_key": "sk-test", "api_base": ""})
+    assert r.status_code == 200
+    body = r.json()
+    assert body["provider"] == "openai"
+    assert body["model"] == "gpt-4o-mini"
+    assert body["has_api_key"] is True
+
+    # persisted in llm_config (single row id=1)
+    with get_conn() as conn:
+        row = conn.execute("SELECT * FROM llm_config WHERE id=1").fetchone()
+    assert row is not None
+    assert row["provider"] == "openai"
+    assert row["model"] == "gpt-4o-mini"
+    assert row["api_key"] == "sk-test"
+
+    # GET /providers reflects the new config
+    prov = client.get("/api/agent/providers").json()
+    assert prov["provider"] == "openai"
+    assert prov["model"] == "gpt-4o-mini"
+    assert prov["has_api_key"] is True
+    # a real provider with a key is marked available (no network call made)
+    assert prov["available"] is True
+
+
+def test_router_patch_providers_requires_admin(client):
+    from app.auth.session import SessionManager
+    from app.db import get_conn
+
+    with get_conn() as conn:
+        conn.execute("INSERT INTO users (login, full_name, is_admin) VALUES ('user_basic', 'Basic', 0)")
+        user = conn.execute("SELECT * FROM users WHERE login='user_basic'").fetchone()
+        conn.commit()
+        sess = SessionManager.create_session(dict(user))
+    client.cookies.set("flowdeck_session", sess)
+
+    r = client.patch("/api/agent/providers", json={"provider": "openai"})
+    assert r.status_code == 403
+
+
+def test_router_providers_test_offline(client):
+    r = client.post("/api/agent/providers/test", json={"provider": "offline"})
+    assert r.status_code == 200
+    assert r.json()["ok"] is True
+
+
+def test_router_providers_test_missing_key(client):
+    # openai without a key must report failure (no mock fallback for the ping)
+    r = client.post("/api/agent/providers/test",
+                    json={"provider": "openai", "api_key": ""})
+    assert r.status_code == 200
+    assert r.json()["ok"] is False
+    assert "clé" in r.json()["error"].lower()
+
+
+def test_router_run_persists_provider_model(client):
+    cid = _make_conversation(client)
+    resp = client.post(f"/api/agent/conversations/{cid}/run",
+                       json={"message": "crée une collection Bilan",
+                             "provider": "openai", "model": "gpt-4o-mini"})
+    assert resp.status_code == 200
+    detail = client.get(f"/api/agent/conversations/{cid}").json()
+    assert detail["conversation"]["provider"] == "openai"
+    assert detail["conversation"]["model"] == "gpt-4o-mini"
 
 
 def _parse_sse(line: str) -> dict: