feat: ADR-0036 Phase 1 — validate advanced-mode INSERT literals + show the value

Capture literal VALUES at parse onto Command::SqlInsert (no grammar change,
no reparse); validate them against column types before the still-verbatim
insert (reusing impl_value_for for DSL-parity wording); read them in the
error enricher so a constraint error names the real value. Execution,
auto-fill, and command identity unchanged. Adds run_sql_insert_with_literals
(runtime path); run_sql_insert stays the no-capture raw entry.

Proven: malformed date 2025/01/15 now refused in advanced-mode SQL; replayed
UNIQUE shows the real value. Tests +3 (expression runs, multi-row, natural
order) + 2 flipped/strengthened. 1930 pass / 0 fail / 0 skip; clippy clean.

tests/undo_snapshots.rs

@@ -273,6 +273,7 @@ async fn sql_insert(db: &Database, input: &str) {
             listed_columns,
             row_source,
             returning,
+            ..
         } => {
             db.run_sql_insert(
                 sql,