feat(seo): implement dynamic metadata, sitemap, and robots.txt

Add dynamic meta tags for routes and entity detail pages
Generate sitemap.xml and robots.txt dynamically in Vite
Change default frontend port from 3000 to 20015

frontend/src/views/RecipeDetail.vue

@@ -11,6 +11,7 @@ import PageHeader from '../components/PageHeader.vue';
 import Skeleton from '../components/Skeleton.vue';
 import Tabs, { type TabOption } from '../components/Tabs.vue';
 import { iconBack, iconEdit, iconRecipe } from '../icons';
+import { applySeo } from '../seo';
 import { api, getAuthToken, type AuthUser, type RecipeDetail } from '../services/api';
 import RecipeEdit from './RecipeEdit.vue';
 
@@ -42,7 +43,17 @@ const recipeSubtitle = computed(() => {
 });
 
 async function loadRecipeDetail() {
-  recipe.value = await api.recipeDetail(String(route.params.id));
+  const nextRecipe = await api.recipeDetail(String(route.params.id));
+  recipe.value = nextRecipe;
+
+  if (route.meta.editorModal !== true) {
+    applySeo({
+      title: `${nextRecipe.name} - ${t('pages.recipes.title')}`,
+      description: t('seo.recipeDetailDescription', { name: nextRecipe.name }),
+      canonicalPath: `/recipes/${nextRecipe.id}`,
+      image: nextRecipe.item.image?.url
+    });
+  }
 }
 
 onMounted(async () => {