fix: update … --all-rows falls back to the DSL instead of misparsing (ADR-0033 Am4)

Advanced-mode `update T set x = 42 --all-rows` parsed the `--all-rows`
DSL flag as the arithmetic `42 - -all - rows` over phantom columns
`all`/`rows` (Amendment 3's counter-example), masked only by the engine's
`--` comment leniency. The playground supports no `--` line comment, so
this was a misparse (ADR-0027: flag input known to fail at runtime).

Fix: walk_punct refuses a `-` that begins an adjacent `--`. Only the SQL
expression uses Node::Punct('-'), so this is scoped to it. The SET
expression then stops, the SQL UPDATE shape fails, and dispatch falls
back to the DSL Update { AllRows } — symmetry with delete … --all-rows.

Behaviour: `42 --all-rows` → DSL Update{AllRows}; spaced `42 - -3` stays
SqlUpdate (= 45, preserved); adjacent `42--3` → parse error (contrived;
no `--` comment support).

Tests: inverted parse test (+ arithmetic-preserved + adjacent-error
assertions); new full-pipeline update_all_rows_flag_in_advanced_updates_every_row.
Suite 1963/0/1; clippy clean.

tests/sql_update.rs

@@ -488,3 +488,38 @@ fn advanced_update_set_expression_still_parses_via_sql_expr() {
         );
     }
 }
+
+// =================================================================
+// ADR-0033 Amendment 4 — `update … --all-rows` falls back to the DSL
+// =================================================================
+
+#[test]
+fn update_all_rows_flag_in_advanced_updates_every_row() {
+    // `update … --all-rows` falls back to the DSL Update { AllRows } in
+    // advanced mode (run_replay parses each line in advanced mode) and
+    // updates every row — the full pipeline end to end, not just the
+    // parse-level dispatch (covered in tests/sql_dml_e2e.rs).
+    let (project, db, _dir) = open_project_db();
+    let rt = rt();
+    create_cols(&db, &rt, "t", &[("id", Type::Int), ("v", Type::Int)], &["id"]);
+    seed(&db, &rt, "insert into t (id, v) values (1, 1), (2, 2)", "t");
+    std::fs::write(
+        project.path().join("allrows.commands"),
+        "update t set v = 9 --all-rows\n",
+    )
+    .expect("write script");
+    let events = rt.block_on(run_replay(&db, project.path(), "allrows.commands"));
+    assert!(
+        matches!(events.last(), Some(AppEvent::ReplayCompleted { count: 1, .. })),
+        "the --all-rows update replays through the DSL fall-back; events: {events:?}"
+    );
+    let rows = rt
+        .block_on(db.query_data("t".to_string(), None, None, None))
+        .expect("query")
+        .rows;
+    assert_eq!(rows.len(), 2, "both rows present");
+    assert!(
+        rows.iter().all(|r| r[1].as_deref() == Some("9")),
+        "every row's v set to 9 (all-rows update); rows: {rows:?}"
+    );
+}