fix(gallery): prevent load button text wrapping in card footer (#43)

* fix(gallery): prevent load button text wrapping in card footer

Add `shrink-0 whitespace-nowrap` to the load button and `min-w-0
truncate` to the filename/scenario span in both FormatCard and
SampleCard. Without these, the span consumed all available flex space
and left the button too narrow to fit its label on one line, causing
the button text to wrap and inflate the card footer height.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(samples-gallery): add title attr to scenario span for truncated text

The truncated label had no tooltip, making long scenario names
inaccessible after clipping. Mirror the same pattern used in
formats-gallery (title={ex.filename}).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>