inner_format_label mapped only IDXD/xml/printable-tag magics; fonts and
images fell through to a bare hex label (00010000, 89504E47, …). Recognize
the known binary signatures and return friendly short tags so the pak
browser's format column reads them: sfnt/true/typ1 → "ttf", OTTO → "otf",
ttcf → "ttc", PNG → "png", plus RIFF/DDS. Still-unidentified magics keep the
hex fallback. Shared by the CLI `pak list` and the GUI browser.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>