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/display.ts

@@ -20,7 +20,7 @@ const FRACTIONS: [number, string][] = [
 ];
 
 /** 0.75 → "¾", 1.5 → "1½", 2.33 → "2⅓", 13.2 → "13". */
-export function formatQuantity(value: number): string {
+function formatQuantity(value: number): string {
   if (value >= 10) return String(Math.round(value));
   const whole = Math.floor(value);
   const fraction = value - whole;
@@ -30,7 +30,7 @@ export function formatQuantity(value: number): string {
   return `${total > 0 ? total : ""}${glyph}` || "0";
 }
 
-export interface IngredientLine {
+interface IngredientLine {
   quantity: string;
   /** e.g. "cup", "lb", or "×" for counted items. */
   unit: string;
@@ -39,7 +39,7 @@ export interface IngredientLine {
   detail?: string;
 }
 
-export function ingredientLine(ingredient: RecipeIngredient, scale: number): IngredientLine {
+function ingredientLine(ingredient: RecipeIngredient, scale: number): IngredientLine {
   const item = CATALOG_BY_ID.get(ingredient.itemId);
   const name = item?.name ?? ingredient.itemId;
   const quantity = formatQuantity(ingredient.amount * scale);