Add Navigation component and integrate it into multiple pages for consistent navigation

frontend/app/recipes/[id]/edit/page.tsx

@@ -5,6 +5,7 @@ import { useRouter, useParams } from 'next/navigation';
 import { fetchJson } from '../../../../lib/api';
 import { parseErrorResponse } from '../../../../lib/error-handler';
 import type { Product, Recipe } from '../../../../features/inventory/types';
+import Navigation from '../../../Navigation';
 
 const MARKDOWN_HELP = `
 **Fetstil:** **text** eller __text__
@@ -181,6 +182,7 @@ export default function EditRecipePage() {
 
   return (
     <main style={{ padding: '1rem', maxWidth: '1000px', margin: '0 auto' }}>
+      <Navigation />
       <h1 style={{ marginBottom: '1rem' }}>Redigera recept</h1>
 
       {error && <p style={{ color: 'crimson', backgroundColor: '#ffe5e5', padding: '0.75rem', borderRadius: '4px', marginBottom: '1rem' }}>{error}</p>}

frontend/app/recipes/create/CreateRecipePage.tsx

@@ -5,6 +5,7 @@ import { useRouter } from 'next/navigation';
 import { fetchJson } from '../../../lib/api';
 import { parseErrorResponse } from '../../../lib/error-handler';
 import type { Product } from '../../../features/inventory/types';
+import Navigation from '../../Navigation';
 
 const MARKDOWN_HELP = `
 **Fetstil:** **text** eller __text__
@@ -136,6 +137,7 @@ export default function CreateRecipePage() {
 
   return (
     <main style={{ padding: '1rem', maxWidth: '1000px', margin: '0 auto' }}>
+      <Navigation />
       <h1 style={{ marginBottom: '1rem' }}>Lägg till nytt recept</h1>
 
       {error && <p style={{ color: 'crimson', backgroundColor: '#ffe5e5', padding: '0.75rem', borderRadius: '4px', marginBottom: '1rem' }}>{error}</p>}

frontend/app/recipes/page.tsx

@@ -2,12 +2,14 @@ import Link from 'next/link';
 import { fetchJson } from '../../lib/api';
 import type { Recipe } from '../../features/inventory/types';
 import RecipePreview from './RecipePreview';
+import Navigation from '../Navigation';
 
 export default async function RecipesPage() {
   const recipes = await fetchJson<Recipe[]>('/api/recipes');
 
   return (
-    <main style={{ padding: '1.5rem', maxWidth: '1000px', margin: '0 auto' }}>
+    <main style={{ padding: '1rem', maxWidth: '1000px', margin: '0 auto' }}>
+      <Navigation />
       <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: '1.5rem' }}>
         <h1 style={{ margin: 0 }}>Recept</h1>
         <Link