0fc7b082b2
ADR-0032 §10.5 — at the cursor, an `<ident>.` prefix narrows column candidates to that qualifier's binding columns. Resolves through from_scope aliases first, then table names, then cte_bindings (for `cte_alias.|`). Falls back to the schema cache for DSL paths (`from <Table>.<col>`). Unresolved qualifier → empty column list; the structural error path surfaces the unresolved-prefix message. Look-ahead probe — the "edit an existing query" workflow. When the cursor is mid-projection but FROM exists after the cursor, a second walk on the full input populates from_scope and the column candidates narrow accordingly. Gated on the leading walk producing no scope so cursor-past-FROM positions pay no cost. The full input must parse for this to work; an unparseable mid-edit state falls back to the §10.6 global posture. CompletionProbe now exposes `from_scope` (top-frame table bindings) and `cte_bindings` (union of in-scope CTE bindings, innermost-first dedupe). The walker drains these at the cursor position; the completion engine reads them for qualifier resolution and unqualified narrowing. Test totals: 1415 → 1424 passing (+9: 5 qualified-prefix + 4 look-ahead). Clippy clean.