feat(help): distinct help for advanced-mode SQL forms; split list by mode (#36)

The six advanced SQL DML/query forms (SELECT, WITH, SQL_INSERT, SQL_UPDATE,
SQL_DELETE, EXPLAIN_SQL) carried help_id: None, so `help select`/`help with`
resolved to nothing and `help insert` showed only the simple form. Give each
its own distinct help_id (data.select, data.sql_insert, …) with a hand-curated
help.data.* page. Distinct strings keep the dedup invariant intact, and
note_help_topic needs no change — `help insert` now shows the simple block and
the sql_insert block (like `help create` already did), and the advanced-only
forms resolve.

note_help now groups the list by CommandCategory: app-lifecycle commands first
(unlabelled), then "Simple-mode commands:" and "Advanced-mode (SQL) commands:"
sections — replacing the old single "DSL data commands (in simple mode):"
header, which used the banned "DSL" term and mis-labelled the advanced SQL
forms it already contained.

Four new help_command tests (red→green). Recorded as ADR-0024 Amendment 1;
CHANGELOG updated.

src/friendly/keys.rs

@@ -180,7 +180,8 @@ pub const KEYS_AND_PLACEHOLDERS: &[(&str, &[&str])] = &[
     // In-app `help` — framing + per-command entries keyed by
     // each CommandNode's `help_id` (ADR-0024 §help_id).
     ("help.intro", &[]),
-    ("help.dsl_section", &[]),
+    ("help.simple_section", &[]),
+    ("help.advanced_section", &[]),
     ("help.types_reference", &[]),
     ("help.detail_hint", &[]),
     ("help.unknown_topic", &["topic"]),
@@ -223,6 +224,13 @@ pub const KEYS_AND_PLACEHOLDERS: &[(&str, &[&str])] = &[
     ("help.data.delete", &[]),
     ("help.data.replay", &[]),
     ("help.data.explain", &[]),
+    // Issue #36: advanced-mode (SQL) help pages.
+    ("help.data.select", &[]),
+    ("help.data.with", &[]),
+    ("help.data.sql_insert", &[]),
+    ("help.data.sql_update", &[]),
+    ("help.data.sql_delete", &[]),
+    ("help.data.explain_sql", &[]),
     // ---- Hint panel ambient typing assistance (ADR-0022 §6) ----
     ("hint.ambient_complete", &[]),
     ("hint.ambient_error_with_usage", &["message", "usage"]),

src/friendly/strings/en-US.yaml

@@ -246,7 +246,13 @@ help:
   # are multi-line-capable — the renderer emits one output row
   # per line so scroll math stays accurate.
   intro: "Supported commands:"
-  dsl_section: "DSL data commands (in simple mode):"
+  # Issue #36: the command list groups by mode. App-lifecycle commands list
+  # first (unlabelled, under the intro — they work in either mode); the rest
+  # split into these two sections by command category. (Replaces the old
+  # single "DSL data commands (in simple mode):" header, which used the banned
+  # "DSL" term and mis-labelled the advanced SQL forms it already contained.)
+  simple_section: "Simple-mode commands:"
+  advanced_section: "Advanced-mode (SQL) commands:"
   # H3: footer on the full `help` list, and the not-found note
   # for `help <topic>`. `{topic}` is the word the user typed.
   detail_hint: "Type `help <command>` for detail on one command (e.g. `help insert`), or `help types` for the type reference."
@@ -368,8 +374,25 @@ help:
         explain show data <T> | explain update <T> ... | explain delete from <T> ...
                                    — show how the database would run a query, without
                                      running it (safe even for update / delete)
-        explain <select|with|insert|update|delete …>  (advanced mode)
-                                   — the same plan for the SQL you wrote
+    # Issue #36: advanced-mode (SQL) forms. Each has its own help page, listed
+    # under the "Advanced-mode (SQL) commands:" section and shown by
+    # `help <topic>` alongside its simple-mode sibling — so `help insert` shows
+    # both the simple form and `sql_insert` (like `help create` already does).
+    select: |-
+        select <cols> | * from <T> [where …] [group by …] [order by …] [limit n]
+                                                         — query rows (advanced SQL)
+    with: |-
+        with <name> as (<select>) [, …] <select>        — query through a named
+                                                           sub-query / CTE (advanced SQL)
+    sql_insert: |-
+        insert into <T> (col, …) values (val, …)        — add a row (advanced SQL)
+    sql_update: |-
+        update <T> set <col> = <val>, … where <expr>    — change matching rows (advanced SQL)
+    sql_delete: |-
+        delete from <T> where <expr>                    — remove matching rows (advanced SQL)
+    explain_sql: |-
+        explain <select|with|insert|update|delete …>    — show the plan for a SQL statement,
+                                                           without running it (advanced SQL)
   # Type reference, appended after the command list.
   types_reference: |
     Types: text, int, real, decimal, bool, date, datetime, blob, serial, shortid