BuildContext nested-input candidate-hint draws from path-origin table instead of @reference terminal table

BuildContext.classifyInputFieldInternal (BuildContext.java:1665-1677) emits a "Did you mean…" hint when a nested-input column name is unresolvable. The candidate list is built from catalog.columnSqlNamesOf(resolvedTable.tableName()) where resolvedTable is the path-origin enclosing input’s @table, not the path’s terminal table.

For an unreachable column under a @reference path field, the candidate suggestions are drawn from the wrong table and lead the user away from the fix. Sibling bug to R233 / R224 on the LSP-arm side, on a different surface.

R224 fixed the LSP diagnostic. R233 (this commit’s parent item) lifts the column dispatch onto FieldClassification.lspColumnDispatch() and routes the LSP completion + hover arms through it. The runtime-side candidate-hint at BuildContext.java:1673 is a different surface (compile-time validator error message vs. LSP arm) and a different audience (the user sees it once at build time, not interactively per keystroke), so it was filed as a separate Backlog item rather than folded into R233.

BuildContext.java:1665-1677 ; the failure-aggregation block walks failures for nested input fields, picks the first one with a non-null lookupColumn, and asks for a candidate hint from resolvedTable.tableName(). For a @reference path field the terminal table on the projected FieldClassification.{ColumnReference,CompositeColumnReference}.tableName() is the right list; the path-origin table is not.

The runtime classifier already projects the terminal table (R224 introduced the projection; R233 lifts it onto lspColumnDispatch()). One option is to route the candidate-hint dispatch through the same FieldClassification projection so the runtime and LSP arms share a single terminal-table source. Another is a narrower fix that looks up the path’s terminal table directly at the call site. Spec-time decision.

LSP arms (covered by R224 + R233). The runtime data-fetcher behaviour (not affected; the column resolution is already correct, only the error message’s candidate list is wrong).