test(cli): ✅ add tests for prune command

add tests for prune command and some code optimization and formatting.

tests/test_mail_reader.py

@@ -114,9 +114,6 @@ class OkAccount:
         self.protocol = OkProtocol()
 
 
-#########################################
-# _find_log_attachment #
-#########################################
 def test_find_log_attachment_returns_log_file(
     empty_mail: Message,
 ):
@@ -221,9 +218,6 @@ def test_find_log_attachment_rejects_non_file_attachment(empty_mail: Message):
     assert attachment is None
 
 
-############################
-# _get_attachment_content #
-############################
 def test_get_attachment_content_decodes_windows_1252(original_log_dir: Path):
     """Decodes content with accents correctly."""
     file_with_accents = original_log_dir / "CR_20260727110008.txt"
@@ -249,9 +243,6 @@ def test_get_attachment_content_empty_bytes():
     assert content == ""
 
 
-########################
-# _get_mail_body(mail) #
-########################
 def test_get_mail_body_from_marker_to_end(empty_mail: Message):
     """Returns body starting at 'Répertoire scanné'."""
     empty_mail.text_body += "Répertoire scanné : \\192.168.60.40\\e$\\MDC_1110\\Logs"
@@ -291,9 +282,6 @@ def test_get_mail_body_multiple_markers(empty_mail: Message):
     assert "Répertoire scanné\nRépertoire scanné\nRépertoire scanné" == content
 
 
-################################
-# _has_attachment_marker(body) #
-################################
 def test_has_attachment_marker_true():
     """Returns True when the exact pattern is present."""
     body_with_pattern = "Compte-rendu du suivi des imports NOSYMAG du 02/09/2026 à 15:00:10\n\nLe compte-rendu contient plus de 100 lignes.\nSe reporter à la pièce jointe."
@@ -318,9 +306,6 @@ def test_has_attachment_marker_empty_string():
     assert not _has_attachment_marker(body_empty)
 
 
-########################
-# connect_to_mailbox() #
-########################
 def test_connect_to_mailbox_success(monkeypatch: MonkeyPatch, caplog, set_env):
     """Returns an Account when credentials are valid."""
     with monkeypatch.context() as m, caplog.at_level(logging.INFO, "logwatcher"):