feat(hint): H2 Phase C batch 1 — app-command tier-3 hints (ADR-0053)

Per-form hints for the 14 app-lifecycle commands (quit/help/hint/
rebuild/save/new/load/export/import/mode/messages/undo/redo/copy),
reference-leaning what/example with concept where it teaches (rebuild,
mode, messages, undo, export, help). hint_ids wired, catalogue + keys.rs
registered. +1 spot test; 2489 pass / 1 ignored, clippy clean.

src/dsl/grammar/app.rs

@@ -266,7 +266,7 @@ pub static QUIT: CommandNode = CommandNode {
     shape: EMPTY_SEQ,
     ast_builder: build_quit,
     help_id: Some("app.quit"),
-    hint_ids: &[],
+    hint_ids: &["quit"],
     usage_ids: &["parse.usage.quit"],};
 
 pub static HELP: CommandNode = CommandNode {
@@ -274,7 +274,7 @@ pub static HELP: CommandNode = CommandNode {
     shape: HELP_TOPIC_OPT,
     ast_builder: build_help,
     help_id: Some("app.help"),
-    hint_ids: &[],
+    hint_ids: &["help"],
     usage_ids: &["parse.usage.help"],};
 
 pub static HINT: CommandNode = CommandNode {
@@ -283,7 +283,7 @@ pub static HINT: CommandNode = CommandNode {
     ast_builder: build_hint,
     help_id: Some("app.hint"),
     // hint_id assigned in Phase C with the tier-3 corpus (ADR-0053).
-    hint_ids: &[],
+    hint_ids: &["hint"],
     usage_ids: &["parse.usage.hint"],};
 
 pub static REBUILD: CommandNode = CommandNode {
@@ -291,7 +291,7 @@ pub static REBUILD: CommandNode = CommandNode {
     shape: EMPTY_SEQ,
     ast_builder: build_rebuild,
     help_id: Some("app.rebuild"),
-    hint_ids: &[],
+    hint_ids: &["rebuild"],
     usage_ids: &["parse.usage.rebuild"],};
 
 pub static SAVE: CommandNode = CommandNode {
@@ -299,7 +299,7 @@ pub static SAVE: CommandNode = CommandNode {
     shape: SAVE_AS_OPT,
     ast_builder: build_save,
     help_id: Some("app.save"),
-    hint_ids: &[],
+    hint_ids: &["save"],
     usage_ids: &["parse.usage.save"],};
 
 pub static NEW: CommandNode = CommandNode {
@@ -307,7 +307,7 @@ pub static NEW: CommandNode = CommandNode {
     shape: EMPTY_SEQ,
     ast_builder: build_new,
     help_id: Some("app.new"),
-    hint_ids: &[],
+    hint_ids: &["new"],
     usage_ids: &["parse.usage.new"],};
 
 pub static LOAD: CommandNode = CommandNode {
@@ -315,7 +315,7 @@ pub static LOAD: CommandNode = CommandNode {
     shape: EMPTY_SEQ,
     ast_builder: build_load,
     help_id: Some("app.load"),
-    hint_ids: &[],
+    hint_ids: &["load"],
     usage_ids: &["parse.usage.load"],};
 
 pub static EXPORT: CommandNode = CommandNode {
@@ -323,7 +323,7 @@ pub static EXPORT: CommandNode = CommandNode {
     shape: EXPORT_PATH_OPT,
     ast_builder: build_export,
     help_id: Some("app.export"),
-    hint_ids: &[],
+    hint_ids: &["export"],
     usage_ids: &["parse.usage.export"],};
 
 pub static IMPORT: CommandNode = CommandNode {
@@ -331,7 +331,7 @@ pub static IMPORT: CommandNode = CommandNode {
     shape: IMPORT_BODY_OPT,
     ast_builder: build_import,
     help_id: Some("app.import"),
-    hint_ids: &[],
+    hint_ids: &["import"],
     usage_ids: &["parse.usage.import"],};
 
 pub static MODE: CommandNode = CommandNode {
@@ -339,7 +339,7 @@ pub static MODE: CommandNode = CommandNode {
     shape: MODE_VALUE,
     ast_builder: build_mode,
     help_id: Some("app.mode"),
-    hint_ids: &[],
+    hint_ids: &["mode"],
     usage_ids: &["parse.usage.mode"],};
 
 pub static MESSAGES: CommandNode = CommandNode {
@@ -347,7 +347,7 @@ pub static MESSAGES: CommandNode = CommandNode {
     shape: MESSAGES_VALUE_OPT,
     ast_builder: build_messages,
     help_id: Some("app.messages"),
-    hint_ids: &[],
+    hint_ids: &["messages"],
     usage_ids: &["parse.usage.messages"],};
 
 pub static UNDO: CommandNode = CommandNode {
@@ -355,7 +355,7 @@ pub static UNDO: CommandNode = CommandNode {
     shape: EMPTY_SEQ,
     ast_builder: build_undo,
     help_id: Some("app.undo"),
-    hint_ids: &[],
+    hint_ids: &["undo"],
     usage_ids: &["parse.usage.undo"],};
 
 pub static REDO: CommandNode = CommandNode {
@@ -363,7 +363,7 @@ pub static REDO: CommandNode = CommandNode {
     shape: EMPTY_SEQ,
     ast_builder: build_redo,
     help_id: Some("app.redo"),
-    hint_ids: &[],
+    hint_ids: &["redo"],
     usage_ids: &["parse.usage.redo"],};
 
 pub static COPY: CommandNode = CommandNode {
@@ -371,5 +371,5 @@ pub static COPY: CommandNode = CommandNode {
     shape: COPY_VALUE_OPT,
     ast_builder: build_copy,
     help_id: Some("app.copy"),
-    hint_ids: &[],
+    hint_ids: &["copy"],
     usage_ids: &["parse.usage.copy"],};