feat(i18n): translate hardcoded strings across print, public recipe, and recipe management UI

Wires dozens of components and server pages to next-intl instead of hardcoded
English text, and adds a lightweight getMessages/formatMessage helper for
server components (print pages, public recipe page, cook metadata) since
next-intl/server isn't wired into this app's routing. Backfills missing
en/fr message keys that existing code already referenced but fr.json lacked.

apps/web/components/social/comments-section.tsx

@@ -3,6 +3,7 @@
 import { useState, useEffect, useCallback } from "react";
 import { MessageCircle, Reply, Trash2 } from "lucide-react";
 import { toast } from "sonner";
+import { useTranslations } from "next-intl";
 import { Button } from "@/components/ui/button";
 import { Textarea } from "@/components/ui/textarea";
 import { Avatar, AvatarFallback, AvatarImage } from "@/components/ui/avatar";
@@ -97,6 +98,7 @@ function CommentItem({
 }) {
   const [showReply, setShowReply] = useState(false);
   const isOwn = comment.userId === currentUserId;
+  const t = useTranslations("social");
 
   async function deleteComment() {
     const res = await fetch(`/api/v1/comments/${comment.id}`, { method: "DELETE" });
@@ -141,7 +143,7 @@ function CommentItem({
               recipeId={recipeId}
               parentId={comment.id}
               onSubmit={() => { setShowReply(false); onRefresh(); }}
-              placeholder="Reply…"
+              placeholder={t("replyPlaceholder")}
               onCancel={() => setShowReply(false)}
             />
           )}
@@ -191,6 +193,7 @@ export function CommentsSection({
 }) {
   const [comments, setComments] = useState<Comment[]>([]);
   const [loading, setLoading] = useState(true);
+  const t = useTranslations("social");
 
   const load = useCallback(async () => {
     const res = await fetch(`/api/v1/recipes/${recipeId}/comments`);
@@ -212,7 +215,7 @@ export function CommentsSection({
       </div>
 
       {currentUserId && (
-        <CommentForm recipeId={recipeId} onSubmit={load} placeholder="Share your thoughts…" />
+        <CommentForm recipeId={recipeId} onSubmit={load} placeholder={t("commentPlaceholder")} />
       )}
 
       {loading ? (