feat(hint): H2 Phase C batch 4 — advanced-mode SQL tier-3 hints (ADR-0053)

Distinct SQL-syntax hints for the 11 advanced-mode forms: sql create
table / alter table / create index / drop index / drop table / insert /
update / delete, select, with, explain. hint_ids wired on all 11 nodes.

Hardened hint_key_for_input_in_mode for shared entry words: a bare
multi-form entry word defers to tier-2; when the second token isn't a
form word (insert into / update … set), it falls back to the
mode-primary key — so advanced mode resolves to the SQL form and simple
mode to the DSL form. catalogue + keys.rs registered. +2 spot tests +
grammar mode-disambiguation asserts; 2495 pass / 1 ignored, clippy clean.

src/app.rs

@@ -5901,6 +5901,27 @@ mod tests {
         assert!(!output_contains(&app, "rows stored in a table"));
     }
 
+    // ── Phase C batch 4: advanced-SQL hints (mode-aware) ────────
+
+    #[test]
+    fn f1_in_advanced_mode_renders_the_sql_insert_hint() {
+        let mut app = App::new();
+        app.mode = Mode::Advanced;
+        type_str(&mut app, "insert into Customers (name) values ('x')");
+        f1(&mut app);
+        assert!(output_contains(&app, "Insert rows with SQL"));
+        assert!(!output_contains(&app, "Add one or more rows"));
+    }
+
+    #[test]
+    fn f1_on_select_renders_the_select_hint() {
+        let mut app = App::new();
+        app.mode = Mode::Advanced;
+        type_str(&mut app, "select name from Customers");
+        f1(&mut app);
+        assert!(output_contains(&app, "heart of SQL"));
+    }
+
     #[test]
     fn messages_command_toggles_verbosity_and_reports() {
         let mut app = App::new();

src/dsl/grammar/data.rs

@@ -1874,7 +1874,7 @@ pub static EXPLAIN_SQL: CommandNode = CommandNode {
     // too). Mirrors the `SQL_INSERT`/`SQL_UPDATE`/`SQL_DELETE`
     // precedent; otherwise `note_help` would print `explain` twice.
     help_id: None,
-    hint_ids: &[],
+    hint_ids: &["explain_sql"],
     usage_ids: &[],};
 
 /// SQL `SELECT` (ADR-0030 §6, ADR-0031, ADR-0032).
@@ -1890,7 +1890,7 @@ pub static SELECT: CommandNode = CommandNode {
     shape: Node::Subgrammar(&sql_select::SQL_SELECT_TAIL),
     ast_builder: build_select,
     help_id: None,
-    hint_ids: &[],
+    hint_ids: &["select"],
     usage_ids: &["parse.usage.select"],};
 
 /// `WITH …` top-level statement (ADR-0032 §4 / sub-phase 2c).
@@ -1905,7 +1905,7 @@ pub static WITH: CommandNode = CommandNode {
     shape: Node::Subgrammar(&sql_select::SQL_WITH_TAIL),
     ast_builder: build_select,
     help_id: None,
-    hint_ids: &[],
+    hint_ids: &["with"],
     usage_ids: &["parse.usage.with"],};
 
 /// SQL `INSERT` — the `Advanced`-category node of the shared
@@ -1923,7 +1923,7 @@ pub static SQL_INSERT: CommandNode = CommandNode {
     shape: Node::Subgrammar(&sql_insert::SQL_INSERT_SHAPE),
     ast_builder: build_sql_insert,
     help_id: None,
-    hint_ids: &[],
+    hint_ids: &["sql_insert"],
     usage_ids: &[],
 };
 
@@ -1937,7 +1937,7 @@ pub static SQL_UPDATE: CommandNode = CommandNode {
     shape: Node::Subgrammar(&sql_update::SQL_UPDATE_SHAPE),
     ast_builder: build_sql_update,
     help_id: None,
-    hint_ids: &[],
+    hint_ids: &["sql_update"],
     usage_ids: &[],
 };
 
@@ -1953,7 +1953,7 @@ pub static SQL_DELETE: CommandNode = CommandNode {
     shape: Node::Subgrammar(&sql_delete::SQL_DELETE_SHAPE),
     ast_builder: build_sql_delete,
     help_id: None,
-    hint_ids: &[],
+    hint_ids: &["sql_delete"],
     usage_ids: &[],
 };
 

src/dsl/grammar/ddl.rs

@@ -1879,7 +1879,7 @@ pub static SQL_CREATE_TABLE: CommandNode = CommandNode {
     shape: Node::Subgrammar(&super::sql_create_table::SQL_CREATE_TABLE_SHAPE),
     ast_builder: build_sql_create_table,
     help_id: Some("ddl.sql_create_table"),
-    hint_ids: &[],
+    hint_ids: &["sql_create_table"],
     usage_ids: &["parse.usage.sql_create_table"],
 };
 
@@ -1899,7 +1899,7 @@ pub static SQL_DROP_TABLE: CommandNode = CommandNode {
     shape: SQL_DROP_TABLE_SHAPE,
     ast_builder: build_sql_drop_table,
     help_id: Some("ddl.sql_drop_table"),
-    hint_ids: &[],
+    hint_ids: &["sql_drop_table"],
     usage_ids: &["parse.usage.sql_drop_table"],
 };
 
@@ -1919,7 +1919,7 @@ pub static SQL_DROP_INDEX: CommandNode = CommandNode {
     shape: SQL_DROP_INDEX_SHAPE,
     ast_builder: build_sql_drop_index,
     help_id: Some("ddl.sql_drop_index"),
-    hint_ids: &[],
+    hint_ids: &["sql_drop_index"],
     usage_ids: &["parse.usage.sql_drop_index"],
 };
 
@@ -2001,7 +2001,7 @@ pub static SQL_CREATE_INDEX: CommandNode = CommandNode {
     shape: SQL_CREATE_INDEX_SHAPE,
     ast_builder: build_sql_create_index,
     help_id: Some("ddl.sql_create_index"),
-    hint_ids: &[],
+    hint_ids: &["sql_create_index"],
     usage_ids: &["parse.usage.sql_create_index"],
 };
 
@@ -2560,7 +2560,7 @@ pub static SQL_ALTER_TABLE: CommandNode = CommandNode {
     shape: SQL_ALTER_TABLE_SHAPE,
     ast_builder: build_sql_alter_table,
     help_id: Some("ddl.sql_alter_table"),
-    hint_ids: &[],
+    hint_ids: &["sql_alter_table"],
     usage_ids: &["parse.usage.sql_alter_table"],
 };
 

src/dsl/grammar/mod.rs

@@ -616,10 +616,13 @@ pub fn usage_keys_for_input_in_mode(
 /// form has no tier-3 block yet (the caller falls back to tier-2).
 #[must_use]
 pub fn hint_key_for_input_in_mode(source: &str, mode: crate::mode::Mode) -> Option<&'static str> {
+    use crate::dsl::walker::lex_helpers::{consume_ident, skip_whitespace};
     let nodes = selected_nodes_for_input_in_mode(source, mode);
     if nodes.is_empty() {
         return None;
     }
+    // Mode-ordered union (advanced-primary first in advanced mode), so a
+    // shared entry word resolves to the surface the user is in.
     let mut keys: Vec<&'static str> = Vec::new();
     for (_, node, _) in &nodes {
         for k in node.hint_ids {
@@ -628,7 +631,25 @@ pub fn hint_key_for_input_in_mode(source: &str, mode: crate::mode::Mode) -> Opti
             }
         }
     }
-    pick_form_key(source, &keys)
+    if keys.is_empty() {
+        return None;
+    }
+    if keys.len() == 1 {
+        return Some(keys[0]);
+    }
+    // A bare multi-form entry word (no form word yet — `add`⏎) has no
+    // chosen form: defer to tier-2, which lists the choices.
+    let start = skip_whitespace(source, 0);
+    if let Some((_, entry_end)) = consume_ident(source, start)
+        && skip_whitespace(source, entry_end) >= source.len()
+    {
+        return None;
+    }
+    // A form word picks the form (`drop column` → `drop_column`); when
+    // the second token isn't a form word (`insert into …`, `update …
+    // set`), fall back to the mode-primary key — in advanced mode the
+    // SQL form, in simple mode the DSL form.
+    pick_form_key(source, &keys).or_else(|| keys.first().copied())
 }
 
 /// Shared mode-aware command-form selection for the entry word at the
@@ -922,6 +943,22 @@ mod hint_key_tests {
             hint_key_for_input_in_mode("drop table T", Mode::Simple),
             Some("drop_table")
         );
+        // Mode picks the surface for a shared entry word whose second
+        // token isn't a form word: SQL form in advanced, DSL in simple.
+        assert_eq!(
+            hint_key_for_input_in_mode("insert into T values (1)", Mode::Advanced),
+            Some("sql_insert")
+        );
+        assert_eq!(
+            hint_key_for_input_in_mode("insert into T values (1)", Mode::Simple),
+            Some("insert")
+        );
+        // `create table` shares a form word — advanced-first ordering
+        // resolves it to the SQL form in advanced mode.
+        assert_eq!(
+            hint_key_for_input_in_mode("create table T (id int)", Mode::Advanced),
+            Some("sql_create_table")
+        );
         // Unknown entry word → None (tier-2 fallback).
         assert_eq!(hint_key_for_input_in_mode("zzz", Mode::Simple), None);
     }

src/friendly/keys.rs

@@ -336,6 +336,40 @@ pub const KEYS_AND_PLACEHOLDERS: &[(&str, &[&str])] = &[
     ("hint.cmd.replay.what", &[]),
     ("hint.cmd.replay.example", &[]),
     ("hint.cmd.replay.concept", &[]),
+    // Phase C batch 4 — advanced-mode SQL command hints.
+    ("hint.cmd.sql_create_table.what", &[]),
+    ("hint.cmd.sql_create_table.example", &[]),
+    ("hint.cmd.sql_create_table.concept", &[]),
+    ("hint.cmd.sql_alter_table.what", &[]),
+    ("hint.cmd.sql_alter_table.example", &[]),
+    ("hint.cmd.sql_alter_table.concept", &[]),
+    ("hint.cmd.sql_create_index.what", &[]),
+    ("hint.cmd.sql_create_index.example", &[]),
+    ("hint.cmd.sql_create_index.concept", &[]),
+    ("hint.cmd.sql_drop_index.what", &[]),
+    ("hint.cmd.sql_drop_index.example", &[]),
+    ("hint.cmd.sql_drop_index.concept", &[]),
+    ("hint.cmd.sql_drop_table.what", &[]),
+    ("hint.cmd.sql_drop_table.example", &[]),
+    ("hint.cmd.sql_drop_table.concept", &[]),
+    ("hint.cmd.sql_insert.what", &[]),
+    ("hint.cmd.sql_insert.example", &[]),
+    ("hint.cmd.sql_insert.concept", &[]),
+    ("hint.cmd.sql_update.what", &[]),
+    ("hint.cmd.sql_update.example", &[]),
+    ("hint.cmd.sql_update.concept", &[]),
+    ("hint.cmd.sql_delete.what", &[]),
+    ("hint.cmd.sql_delete.example", &[]),
+    ("hint.cmd.sql_delete.concept", &[]),
+    ("hint.cmd.select.what", &[]),
+    ("hint.cmd.select.example", &[]),
+    ("hint.cmd.select.concept", &[]),
+    ("hint.cmd.with.what", &[]),
+    ("hint.cmd.with.example", &[]),
+    ("hint.cmd.with.concept", &[]),
+    ("hint.cmd.explain_sql.what", &[]),
+    ("hint.cmd.explain_sql.example", &[]),
+    ("hint.cmd.explain_sql.concept", &[]),
     (
         "hint.ambient_invalid_ident",
         &["kind", "found"],

src/friendly/strings/en-US.yaml

@@ -545,6 +545,52 @@ hint:
       what: "Re-run the commands recorded in a history file."
       example: "replay session.log"
       concept: "Every successful command is journalled, so replaying re-applies them in order to reproduce a project's state — handy for scripting or redoing a sequence."
+    # Advanced-mode SQL forms (Phase C batch 4). Examples are SQL, the
+    # advanced surface — distinct from their simple-mode siblings.
+    sql_create_table:
+      what: "Create a table using SQL syntax (advanced mode)."
+      example: "create table Customers (id int primary key, name text, email text)"
+      concept: "Advanced mode speaks SQL: constraints go inline (`primary key`, `not null`, `unique`, `check`). This is the raw form of simple mode's `create table … with pk …`."
+    sql_alter_table:
+      what: "Change a table's structure with SQL `alter table` (advanced mode)."
+      example: "alter table Customers add column phone text"
+      concept: "`alter table` adds or drops columns, renames, and adds constraints — the SQL equivalent of simple mode's `add column` / `drop column` / `change column`."
+    sql_create_index:
+      what: "Create an index with SQL (advanced mode)."
+      example: "create index ix_email on Customers (email)"
+      concept: "Add `unique` to also forbid duplicate values. The simple-mode equivalent is `add index`."
+    sql_drop_index:
+      what: "Remove an index with SQL (advanced mode)."
+      example: "drop index ix_email"
+      concept: "Only the lookup shortcut goes; the data is untouched. Add `if exists` to ignore a missing index."
+    sql_drop_table:
+      what: "Remove a table with SQL (advanced mode)."
+      example: "drop table Customers"
+      concept: "Add `if exists` to avoid an error when the table might not be there. Relationships pointing at it may block the drop."
+    sql_insert:
+      what: "Insert rows with SQL (advanced mode)."
+      example: "insert into Customers (name, email) values ('Ann', 'ann@example.io')"
+      concept: "Naming the columns lets you supply them in any order and skip ones that have a default — the SQL form of simple mode's `insert`."
+    sql_update:
+      what: "Update rows with SQL (advanced mode)."
+      example: "update Customers set email = 'new@example.io' where id = 1"
+      concept: "`set` lists the new values; `where` picks which rows change. The SQL form of simple mode's `update`."
+    sql_delete:
+      what: "Delete rows with SQL (advanced mode)."
+      example: "delete from Orders where status = 'cancelled'"
+      concept: "`where` picks the rows to remove; foreign-key rules still apply. The SQL form of simple mode's `delete`."
+    select:
+      what: "Query rows with SQL `select` (advanced mode)."
+      example: "select name, email from Customers where id = 1"
+      concept: "`select` is read-only: choose columns (or `*`), filter with `where`, sort with `order by`, cap with `limit`. This is the heart of SQL — and the reason advanced mode exists."
+    with:
+      what: "Name a sub-query (a CTE) and read from it in a `select` (advanced mode)."
+      example: "with recent as (select * from Orders where id > 100) select * from recent"
+      concept: "A `with` clause (Common Table Expression) names a query so the main `select` can use it like a temporary table — handy for breaking a complex query into readable steps."
+    explain_sql:
+      what: "Show how the database will run a SQL query, without running it (advanced mode)."
+      example: "explain select * from Customers where email = 'a@example.io'"
+      concept: "Like simple mode's `explain`, but wraps a raw SQL statement. It reveals whether an index is used, and never executes."
   err:
     foreign_key:
       child_side: