feat(abonnement): linkedin_button paramétrable par next, inscription vers mes-infos

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/test_linkedin_button.py

@@ -0,0 +1,27 @@
+def test_linkedin_button_default_has_no_next():
+    # Import app first to initialize Dash
+    from src.app import app  # noqa: F401
+    from src.pages.connexion import linkedin_button
+
+    html_str = str(linkedin_button())
+    assert "href='/auth/linkedin'" in html_str
+    assert "next=" not in html_str
+
+
+def test_linkedin_button_with_next_appends_query():
+    # Import app first to initialize Dash
+    from src.app import app  # noqa: F401
+    from src.pages.connexion import linkedin_button
+
+    html_str = str(linkedin_button("/compte/abonnement/mes-infos"))
+    assert "/auth/linkedin?next=/compte/abonnement/mes-infos" in html_str
+
+
+def test_inscription_linkedin_targets_mes_infos():
+    # Import app first to initialize Dash
+    from src.app import app  # noqa: F401
+    from src.pages import inscription
+
+    assert "/auth/linkedin?next=/compte/abonnement/mes-infos" in str(
+        inscription.layout()
+    )