A name resolved through an export list (or a default-export identifier)
mapped back to its whole VariableStatement, and checkDecl walked every
declarator — so a private sibling sharing the statement with an exported
const was wrongly required to carry JSDoc.
The scope dispatch is now two-phase: requests accumulate per statement
(null = whole statement for a direct export modifier or ambient scope;
name sets union across lists, so two lists naming different declarators
of one statement both count), then each surfaced statement is checked
once with the declarator filter. Regressions pin the private-sibling
skip, the cross-list union, and the default-export sibling.