feat: add craft-goal session starter and command

Adds /craft-goal autocomplete and chat handling for starting a Goal crafting session.
Introduces new Magic Prompts content and localized labels/descriptions for Goal crafting.
Migrates desktop draft starters to include Craft a Goal once and persists the migration marker.

packages/ui/src/lib/api/types.ts

@@ -674,6 +674,7 @@ export interface SettingsPayload {
   pwaAppName?: string;
   mobileKeyboardMode?: 'native' | 'resize-content';
   draftStarters?: DraftStarterRef[];
+  draftStartersCraftGoalAdded?: boolean;
 
   [key: string]: unknown;
 }