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/recipe/recipe-chat-panel.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { useState, useRef, useEffect } from "react";
+import { useTranslations } from "next-intl";
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Sheet, SheetContent, SheetHeader, SheetTitle } from "@/components/ui/sheet";
@@ -19,6 +20,7 @@ type Props = {
 };
 
 export function RecipeChatPanel({ recipeId, recipeTitle }: Props) {
+  const t = useTranslations("recipeChat");
   const [open, setOpen] = useState(false);
   const [messages, setMessages] = useState<Message[]>([]);
   const [input, setInput] = useState("");
@@ -49,12 +51,12 @@ export function RecipeChatPanel({ recipeId, recipeTitle }: Props) {
       const data = await res.json() as { answer?: string; error?: string };
       setMessages((prev) => [
         ...prev,
-        { role: "assistant", content: data.answer ?? "Sorry, I couldn't answer that." },
+        { role: "assistant", content: data.answer ?? t("sorry") },
       ]);
     } catch {
       setMessages((prev) => [
         ...prev,
-        { role: "assistant", content: "Something went wrong. Please try again." },
+        { role: "assistant", content: t("error") },
       ]);
     } finally {
       setLoading(false);
@@ -62,10 +64,10 @@ export function RecipeChatPanel({ recipeId, recipeTitle }: Props) {
   };
 
   const suggestions = [
-    "Can I substitute any ingredients?",
-    "How do I know when it's done?",
-    "Can I make this ahead of time?",
-    "What can I serve with this?",
+    t("suggestion1"),
+    t("suggestion2"),
+    t("suggestion3"),
+    t("suggestion4"),
   ];
 
   return (
@@ -75,7 +77,7 @@ export function RecipeChatPanel({ recipeId, recipeTitle }: Props) {
         size="icon"
         className="fixed bottom-6 right-6 h-12 w-12 rounded-full shadow-lg z-40"
         onClick={() => setOpen(true)}
-        aria-label="Ask AI about this recipe"
+        aria-label={t("ariaLabel")}
       >
         <MessageCircle className="h-5 w-5" />
       </Button>
@@ -85,7 +87,7 @@ export function RecipeChatPanel({ recipeId, recipeTitle }: Props) {
           <SheetHeader className="px-4 py-3 pr-10 border-b shrink-0">
             <SheetTitle className="text-base flex items-center gap-2">
               <Bot className="h-4 w-4 text-primary" />
-              Ask about this recipe
+              {t("title")}
             </SheetTitle>
             <p className="text-xs text-muted-foreground text-left">{recipeTitle}</p>
           </SheetHeader>
@@ -94,7 +96,7 @@ export function RecipeChatPanel({ recipeId, recipeTitle }: Props) {
             {messages.length === 0 && (
               <div className="space-y-3">
                 <p className="text-sm text-muted-foreground text-center py-4">
-                  Ask anything about this recipe — ingredients, techniques, substitutions, timing…
+                  {t("intro")}
                 </p>
                 <div className="space-y-2">
                   {suggestions.map((s) => (
@@ -163,7 +165,7 @@ export function RecipeChatPanel({ recipeId, recipeTitle }: Props) {
             <Input
               value={input}
               onChange={(e) => setInput(e.target.value)}
-              placeholder="Ask a question…"
+              placeholder={t("inputPlaceholder")}
               disabled={loading}
               className="flex-1"
               autoComplete="off"