feat(hint): H2 Phase C batch 2 — DDL tier-3 hints (ADR-0053)

Per-form hints for the schema-shaping commands: create table, create
m:n, add column/index/constraint, drop table/column/relationship/
index/constraint, rename column, change column (add_relationship was
the Phase-B exemplar). Examples verified against the canonical usage
templates. hint_ids wired on CREATE/CREATE_M2N/DROP/RENAME/CHANGE;
catalogue + keys.rs registered. +2 spot tests (incl. multi-form DROP
disambiguation); 2491 pass / 1 ignored, clippy clean.

src/app.rs

@@ -5862,6 +5862,26 @@ mod tests {
         );
     }
 
+    // ── Phase C batch 2: DDL hints render (incl. multi-form DROP) ──
+
+    #[test]
+    fn f1_on_create_table_renders_its_hint_block() {
+        let mut app = App::new();
+        type_str(&mut app, "create table Customers with pk id(serial)");
+        f1(&mut app);
+        assert!(output_contains(&app, "Create a new table"));
+    }
+
+    #[test]
+    fn f1_disambiguates_drop_forms() {
+        let mut app = App::new();
+        type_str(&mut app, "drop index idx_email");
+        f1(&mut app);
+        // Resolves drop_index, not drop_table/column/etc.
+        assert!(output_contains(&app, "Remove an index by name"));
+        assert!(!output_contains(&app, "Remove a table"));
+    }
+
     #[test]
     fn messages_command_toggles_verbosity_and_reports() {
         let mut app = App::new();