Move UI to BoardUI with slate + salmon theme; add PDF plan export

- Adopt BoardUI (Pro init): theme tokens, Inter, .dark mode, Button,
  SegmentedControl, Meter, Skeleton and ThemeToggle; remap the app's
  color aliases onto BoardUI tokens and swap lucide for Remix icons
- Retint BoardUI's neutral ramp to cool slate with a salmon accent;
  drop the dotted background; raise muted text contrast
- Simplify the landing page and remove the overlap explorer
- Planner: explicit "I have this" toggle on grocery lines, pantry panel
  above the menu with the staples list spelled out, sticky aisle
  header fix, and a "Download PDF" plan export (jsPDF, lazy-loaded)
- Recipes: replace the family cabbage soup with Cade's Cabbage Soup
  (adds Bone-In Ham Steak to the catalog); remove Ham, Bean & Cabbage Soup
- Remove unused BoardUI components, dependencies and exports

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/lib/plan.ts

@@ -56,7 +56,7 @@ export const slotKey = (dayIndex: number, mealNumber: number) => `${dayIndex}-${
  * So changing the count never moves a meal to a different slot, and meals
  * hidden by a lower count come back when you raise it again (like days do).
  */
-export const MEAL_NAMES = ["Breakfast", "Lunch", "Dinner"] as const;
+const MEAL_NAMES = ["Breakfast", "Lunch", "Dinner"] as const;
 
 /** Visible meal numbers for a count, e.g. 2 → [2, 3]. */
 export function visibleMeals(mealsPerDay: number): number[] {
@@ -107,7 +107,7 @@ export function activeRecipeIds(state: Pick<MealPlanState, "daysCount" | "mealsP
 
 // --- Can this recipe be planned? ---------------------------------------------
 
-export interface RecipeBlockers {
+interface RecipeBlockers {
   /** Appliance labels the user doesn't have, e.g. ["Oven"]. */
   missingAppliances: string[];
   /** Store-item names the user chose to avoid, e.g. ["80/20 Ground Beef"]. */