exec: use localized strings for catalog chrome

docs/CHANGELOG.md

@@ -64,6 +64,8 @@
   around the command-catalog rows.
 - The full-screen key reference now uses the shared localized-string helper
   around the command-catalog rows.
+- SSH exec help headers and usage prefixes now use the shared
+  localized-string helper and English fallback path.
 - Documented i18n and user-facing text rules for English-first source text,
   stable command syntax, concise help copy, and translation-only localization.
 

src/exec_catalog.c

@@ -134,11 +134,11 @@ bool exec_catalog_args_valid(tnt_exec_command_id_t id, const char *args) {
 
 void exec_catalog_append_help(char *buffer, size_t buf_size, size_t *pos,
                               ui_lang_t lang) {
-    if (lang == UI_LANG_ZH) {
-        buffer_appendf(buffer, buf_size, pos, "TNT exec 接口\n命令:\n");
-    } else {
-        buffer_appendf(buffer, buf_size, pos, "TNT exec interface\nCommands:\n");
-    }
+    static const i18n_string_t header =
+        I18N_STRING("TNT exec interface\nCommands:\n",
+                    "TNT exec 接口\n命令:\n");
+
+    buffer_appendf(buffer, buf_size, pos, "%s", i18n_string(header, lang));
 
     for (size_t i = 0; i < sizeof(entries) / sizeof(entries[0]); i++) {
         const char *summary = i18n_string(entries[i].summary, lang);
@@ -150,15 +150,12 @@ void exec_catalog_append_help(char *buffer, size_t buf_size, size_t *pos,
 void exec_catalog_append_usage(char *buffer, size_t buf_size, size_t *pos,
                                tnt_exec_command_id_t id, ui_lang_t lang) {
     const exec_catalog_entry_t *entry = entry_for_id(id);
+    static const i18n_string_t usage_format =
+        I18N_STRING("%s: usage: %s\n", "%s: 用法: %s\n");
 
     if (!entry) {
         return;
     }
-    if (lang == UI_LANG_ZH) {
-        buffer_appendf(buffer, buf_size, pos, "%s: 用法: %s\n",
-                       entry->name, entry->usage_syntax);
-        return;
-    }
-    buffer_appendf(buffer, buf_size, pos, "%s: usage: %s\n",
+    buffer_appendf(buffer, buf_size, pos, i18n_string(usage_format, lang),
                    entry->name, entry->usage_syntax);
 }

tests/unit/test_exec_catalog.c

@@ -107,6 +107,12 @@ TEST(generates_localized_usage) {
 
     assert(strcmp(en, "tail: usage: tail [N] | tail -n N\n") == 0);
     assert(strcmp(zh, "post: 用法: post MESSAGE\n") == 0);
+
+    memset(en, 0, sizeof(en));
+    en_pos = 0;
+    exec_catalog_append_usage(en, sizeof(en), &en_pos,
+                              TNT_EXEC_COMMAND_TAIL, (ui_lang_t)99);
+    assert(strcmp(en, "tail: usage: tail [N] | tail -n N\n") == 0);
 }
 
 int main(void) {