Correct partial table types

`_display_data` is a cache keyed by force name, not a single record.
The auto complete accumulator starts empty, so its fields are optional.
Game commands have no usage beyond their own help text.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

exp_commands/module/search.lua

@@ -49,7 +49,8 @@ function Search.prepare(custom_commands)
         command_objects[name] = {
             name = name,
             description = locale_desc,
-            help_text = locale_desc,
+            help_text = locale_desc,
+            usage = locale_desc,
             aliases = {},
         }
     end