The tool-cards change (#593) tightened _md_line_has_box_drawing to exempt
pure-horizontal '─' runs as markdown hr. But a SIMPLE-box Markdown table's
only box glyph is its header rule, so that exemption dropped whole tables
out of the passthrough copy path and into the wide-render aligner, which
maps selection cell-columns to character indices — misaligning copy of any
table with CJK (wide) cells.
Remove the pure-horizontal exemption so a table's header rule is detected
again and the table run stays passthrough. Card gutters (└─ / │ / └) keep
their own prefix-based exemptions, so tool cards are unaffected. The only
cost is a real markdown hr copying as a dash run — the pre-#593 behavior.
nianyucatfish
262614cafd
