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/components/MealGrid.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { AlertTriangle, ArrowLeftRight, Plus, X } from "lucide-react";
+import { RiAlertLine as AlertTriangle, RiArrowLeftRightLine as ArrowLeftRight, RiAddLine as Plus, RiCloseLine as X } from "@remixicon/react";
 import { useState, type Dispatch } from "react";
 import { APPLIANCES, DAY_NAMES, activeSlots, describeBlockers, isCookable, mealLabel, recipeBlockers, slotKey } from "@/app/lib/plan";
 import { RECIPES_BY_ID } from "@/app/lib/recipes";
@@ -47,7 +47,7 @@ export function MealGrid({ state, dispatch, mealCosts, onOpenSlot, onViewSlot, o
           const hasAnyMeal = slots.some((s) => s.recipeId !== null);
 
           return (
-            <article key={day} className="flex flex-col overflow-hidden rounded-xl border border-line bg-surface">
+            <article key={day} className="flex flex-col overflow-hidden rounded-3xl border border-border-button-default bg-surface">
               {/* Architectural day header */}
               <div className="flex items-baseline justify-between border-b border-line bg-raised/65 px-4 py-2.5">
                 <h3 className="font-serif text-base font-semibold tracking-tight text-ink">{DAY_NAMES[day]}</h3>