Fix plan: drop dead test helper in Task 8

docs/superpowers/plans/2026-07-09-langflow-projekt-matching.md

@@ -1652,21 +1652,6 @@ from projektmatch import ingest
 from projektmatch.config import Cfg
 
 
-def make_mailbox(mails):
-    """mails: {uid: (subject, html)}"""
-    box = mock.Mock()
-    box.unchecked_uids.return_value = list(mails)
-    def fetch(uid):
-        subject, html = mails[uid]
-        msg = mock.Mock()
-        msg.__getitem__ = lambda self, k: subject
-        msg.get = lambda k, d=None: subject
-        box_html[uid] = html
-        return msg
-    box.fetch.side_effect = fetch
-    return box
-
-
 PROJECT_HTML = ('<a href="https://www.freelancermap.de/nproj/1.html?x=1">'
                 'Projekt Eins</a>')