fix: move fitness goals to Settings, clean up mobile nav

- Removed fitness sub-pages from mobile More sheet (Food Library and
  Quick Meals are already tabs on the fitness page)
- Added Fitness Goals section to Settings page with inline editing
- Goals show current values with Edit Goals button
- Edit mode: 2x2 grid with calorie/protein/carbs/fat inputs
- Save calls PUT /api/fitness/goals
- Works for both users independently

frontend-v2/src/lib/components/layout/MobileTabBar.svelte

@@ -1,6 +1,6 @@
 <script lang="ts">
 	import { page } from '$app/state';
-	import { LayoutDashboard, DollarSign, Package, Activity, MoreVertical, MapPin, BookOpen, Library, Settings, Target, UtensilsCrossed, Zap } from '@lucide/svelte';
+	import { LayoutDashboard, DollarSign, Package, Activity, MoreVertical, MapPin, BookOpen, Library, Settings } from '@lucide/svelte';
 
 	interface Props {
 		visibleApps?: string[];
@@ -66,21 +66,7 @@
 					Trips
 				</a>
 			{/if}
-			{#if showApp('fitness')}
-				<a href="/fitness/foods" class="more-sheet-item" onclick={closeMore}>
-					<UtensilsCrossed size={20} />
-					Food Library
-				</a>
-				<a href="/fitness/goals" class="more-sheet-item" onclick={closeMore}>
-					<Target size={20} />
-					Fitness Goals
-				</a>
-				<a href="/fitness/templates" class="more-sheet-item" onclick={closeMore}>
-					<Zap size={20} />
-					Quick Meals
-				</a>
-			{/if}
-			{#if showApp('reader')}
+				{#if showApp('reader')}
 				<a href="/reader" class="more-sheet-item" onclick={closeMore}>
 					<BookOpen size={20} />
 					Reader