Mirror Phase 1's capture-at-parse technique on the UPDATE SET assignment
list. build_sql_update calls the new capture_set_literals (data.rs), which
walks the matched tokens (no reparse, no grammar change) and classifies
each top-level `SET col = <rhs>` as a literal (Some, incl. signed numbers)
or an expression (None), using paren depth so a comma inside a function
call or a `where` inside a scalar subquery is not mistaken for a boundary,
and the trailing top-level WHERE is excluded.
Command::SqlUpdate gains set_literals; do_sql_update validates the literals
against their column types via the shared impl_value_for before the still
verbatim update; user_value_for_column reads them so a constraint error
names the offending value. WHERE stays unvalidated; execution and command
identity are unchanged.
Also corrects the stale data.rs header comment (DSL typed slots are wired,
not "deferred") and flips ADR-0036 + README to Phases 1–2 implemented.
Tests: 1934 passing (+4), 0 failed, 0 skipped, 1 ignored; clippy clean.
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.
claude@clouddev1