A no-column-list (natural-order / Form B) SQL INSERT that hit a UNIQUE/
CHECK violation degraded to the neutral "that value" because
user_value_for_column only resolved the offending value for the explicit-
column-list form. Extend user_value_for_column_with_schema to map each
VALUES position to the schema's columns in declaration order (ALL columns
— advanced-mode Form B auto-fills nothing, so every column has a value),
single-row only (multi-row stays ambiguous). Closes the Phase 1 carryover
gap so the error names the real value either way.
Tests: 1948 passing (+1), 0 failed, 0 skipped, 1 ignored; clippy clean.
claude@clouddev1
d98717156e