feat(dictionary): add Hachidori backend support

- Add backend selection, setup gating, Anki integration, and external host support
- Add launcher flags, documentation, packaging, and focused tests
- Open on-demand overlay modals on the first attempt

src/main/cli-runtime.ts

@@ -49,6 +49,7 @@ export interface CliCommandRuntimeServiceContext {
   runYoutubePlaybackFlow: CliCommandRuntimeServiceDepsParams['app']['runYoutubePlaybackFlow'];
   ensureBackgroundStatsServer?: CliCommandRuntimeServiceDepsParams['app']['ensureBackgroundStatsServer'];
   openYomitanSettings: () => void;
+  openHachidoriSettings: () => void;
   openConfigSettingsWindow: () => void;
   openSyncUiWindow: () => void;
   cycleSecondarySubMode: () => void;
@@ -135,6 +136,7 @@ function createCliCommandDepsFromContext(
     ui: {
       openFirstRunSetup: context.openFirstRunSetup,
       openYomitanSettings: context.openYomitanSettings,
+      openHachidoriSettings: context.openHachidoriSettings,
       openConfigSettingsWindow: context.openConfigSettingsWindow,
       openSyncUiWindow: context.openSyncUiWindow,
       cycleSecondarySubMode: context.cycleSecondarySubMode,