grammar+db: 3b — SQL INSERT grammar + minimal execution (ADR-0033 §1)

SQL_INSERT_SHAPE (INTO <table> [(cols)] VALUES tuple(s)) with __rdbms_*
target rejection; Command::SqlInsert{sql,target_table}; Request::RunSqlInsert
+ do_sql_insert worker (tx-guarded: execute, then finalize_persistence for
CSV + history before commit, so failures roll back and don't re-persist).
Auto-show is best-effort via last_insert_rowid range.

Isolated behind a dev `sqlinsert` entry word (Advanced) so the SQL path is
testable without making `insert` a shared word yet (that's 3j, after 3d
auto-fill parity). Command::SqlInsert carries only sql+target_table; the
plan's listed_columns/returning land in 3d/3g where they're read.

6 grammar accept/reject tests + 8 integration tests (single/multi-row,
column-list, full-arity, history, rollback-on-failure, multi-row atomicity,
parse-path reconstruction, internal-table rejection). 1452 baseline green.

tests/typing_surface/mod.rs

@@ -219,6 +219,7 @@ fn command_kind_label(cmd: &rdbms_playground::dsl::Command) -> String {
         Replay { .. } => "Replay".into(),
         Explain { .. } => "Explain".into(),
         Select { .. } => "Select".into(),
+        SqlInsert { .. } => "SqlInsert".into(),
         App(app) => match app {
             AppCommand::Quit => "App(Quit)".into(),
             AppCommand::Help => "App(Help)".into(),