refactor(components): remove md-commander widget

The journal now owns command history and tracking, so retire the md-commander widget. Its dice engine was extracted to src/components/dice in the previous commit.

Removes the custom element, tracker/command stores, completions, useCommander, Emmet parser, the doc entry, test fixtures, and the known-element catalog entry (reference docs regenerated).

BREAKING CHANGE: :md-commander is no longer a known element; content using it now fails tttk check with TTTK-D001.

src/components/index.ts

@@ -8,7 +8,6 @@ import "./md-border";
 import "./md-font";
 import "./md-embed";
 import "./md-deck";
-import "./md-commander/index";
 import "./md-yarn-spinner";
 
 // 导出组件
@@ -33,29 +32,3 @@ export type { FontProps } from "./md-font";
 export type { BorderProps } from "./md-border";
 export type { EmbedProps } from "./md-embed";
 export type { YarnSpinnerProps } from "./md-yarn-spinner";
-
-// 导出 md-commander 相关
-export type {
-  MdCommanderProps,
-  MdCommanderCommand,
-  MdCommanderCommandMap,
-  MdCommanderParameter,
-  MdCommanderOption,
-  MdCommanderOptionType,
-  CommanderEntry,
-  CompletionItem,
-  TrackerItem,
-  TrackerAttribute,
-  TrackerAttributeType,
-  TrackerCommand,
-  TrackerViewMode,
-} from "./md-commander/types";
-export { TabBar } from "./md-commander/TabBar";
-export { TrackerView } from "./md-commander/TrackerView";
-export { CommanderEntries } from "./md-commander/CommanderEntries";
-export { CommanderInput } from "./md-commander/CommanderInput";
-export { useCommander } from "./md-commander/hooks";
-export {
-  initializeCommands,
-  getCommands,
-} from "./md-commander/stores/commandsStore";