feat: ADR-0035 Amendment 1 follow-up — enrich replay errors + close message gaps

- F2-broad: replay failures now render with real schema context instead of
  a contextless friendly_message(). Extract App::build_translate_context into
  the shared App::translate_context_for(command, facts, verbosity); run_replay
  enriches via enrich_dsl_failure + that builder. ctx_* fallbacks degrade to
  neutral prose so the rare non-replay contextless callsites can't leak raw
  {name} either. (SQL INSERT/UPDATE values aren't retained — ADR-0033 verbatim
  — so those show real table/column + neutral "that value".)
- Gap C: SQL ALTER … ADD FOREIGN KEY on a missing child column refuses with an
  SQL-appropriate "add it first", not the DSL-only --create-fk flag.
- Gap B: dropping a single-column-UNIQUE column refuses with a pointer to
  `drop constraint unique from T.col` (was an opaque generic refusal).
- Gap D: 4e drop/rename CHECK-guard + 4f change-type FK-guard refusals reworded
  to explain why; static_refusal reasons left as-is.

Tests: +4, 3 strengthened. 1926 pass / 0 fail / 0 skip; clippy clean.

tests/sql_alter_table.rs

@@ -613,6 +613,34 @@ fn e2e_drop_composite_unique_is_one_undo_step() {
     assert!(has_unique(), "one undo restored the composite UNIQUE");
 }
 
+#[test]
+fn e2e_add_foreign_key_missing_child_column_refuses_without_dsl_flag() {
+    // Gap C (ADR-0035 Amendment 1): the SQL ADD FOREIGN KEY refusal for a
+    // missing child column must speak SQL — not suggest the DSL-only
+    // `--create-fk` flag (which `do_add_relationship` mentions for the
+    // simple `add relationship` surface).
+    let (project, db, _d) = open();
+    let r = rt();
+    std::fs::write(
+        project.path().join("fk.commands"),
+        "create table P with pk id(int)\n\
+         create table C with pk cid(int)\n\
+         alter table C add foreign key (pid) references P(id)\n",
+    )
+    .expect("write");
+    let events = r.block_on(run_replay(&db, project.path(), "fk.commands"));
+    let AppEvent::ReplayFailed { error, .. } = events.last().expect("an event") else {
+        panic!("expected ReplayFailed; events: {events:?}");
+    };
+    assert!(!error.contains("--create-fk"), "no DSL flag in the SQL refusal; got: {error}");
+    assert!(error.contains("pid"), "names the missing column; got: {error}");
+    assert!(
+        error.to_lowercase().contains("add it first")
+            || error.to_lowercase().contains("does not exist"),
+        "actionable wording; got: {error}"
+    );
+}
+
 #[test]
 fn e2e_add_foreign_key_creates_an_enforced_relationship() {
     let (project, db, _d) = open();