Development record

Two regressions introduced by the sixth-round fixes: confining the setext scan to the frontmatter offset trusts a closer that overshoots into the body, so a record whose first block is closed by three dots or never closed lets a setext excluded heading travel whole (refused before the fix); and anchoring the flow-mapping scan to a brace that opens the line reopens nested flow keys — a key after a newline inside braces, a flow map in a sequence item, a flow map in a flow sequence — all admitted while the fifth-round record claims them refused. Restore the narrow skip (only an indented line in the first block, or refuse a dots-closed or unclosed first block) and widen the flow anchor or track brace depth across the first block.