Edge-probe now surfaces a zero-classification requirement (non-empty prose, no
shape cue matched, no `shapes` override) as a single soft `unclassified — review
manually` candidate instead of silently dropping it — the exact blind spot the
probe exists to catch. Dismissible like any edge; the `shapes: []` opt-out stays
silent; `TAXONOMY` (the closed 8 categories) is unchanged. Under `--auto` the
candidate is left `unresolved`, never auto-`backstop` (a missing shape is not
evidence an edge exists).
Closes#1110
3556450b0d