feat(i18n): resolve Species/Breed display names via SpeciesTranslation/BreedTranslation

User found "Cat" showing English on a German-locale profile page. Root
cause: Species.name/Breed.name are the canonical English values; a
SpeciesTranslation/BreedTranslation table + seed data (Hund/Katze/Vogel
etc.) already existed in the schema, and PetForm's species/breed picker
already used it correctly via an explicit locale input param — but every
*display* surface (pet profile, PetCard, Sidebar/MobileNav, search,
explore, followers/following lists, mention @-search, health-card) just
read the raw untranslated name.

Adds `locale` to the tRPC context (createTRPCContext reads the
NEXT_LOCALE cookie the same way i18n/request.ts does), so read
procedures can resolve translations without every caller needing to
pass a locale param. New src/lib/localized-name.ts::pickLocalizedName()
does the lookup with a same-shape fallback to the raw name.

Updated: pets.ts (list/byId/getProfile/update), search.ts (pets/byOwner),
explore.ts (listPets), follows.ts (listFollowers/listFollowing).
health-card/[token]/page.tsx (public, unauthenticated, intentionally
all-German) resolves with a fixed "de" locale instead of ctx.locale,
consistent with its existing hardcoded WeightChart locale.

Verified the seed data is actually present in the production DB
(SpeciesTranslation has Dog→Hund, Cat→Katze, Bird→Vogel) — this fix is
immediately effective on deploy, not blocked on a missing seed run.

src/trpc/init.ts

@@ -1,14 +1,24 @@
 import { initTRPC, TRPCError } from "@trpc/server";
 import { auth } from "@clerk/nextjs/server";
+import { cookies } from "next/headers";
 import { prisma } from "@/lib/prisma";
+import { LOCALES, defaultLocale } from "@/i18n/request";
 
 /**
  * tRPC context — created per request in the API route handler.
  * Reads the authenticated owner's Clerk userId and provides the Prisma client.
+ *
+ * `locale` mirrors the NEXT_LOCALE cookie resolution in i18n/request.ts, so
+ * procedures that return DB-stored, translatable text (Species/Breed names —
+ * see SpeciesTranslation/BreedTranslation) can resolve the right language
+ * without every caller having to pass a locale input param explicitly.
  */
 export const createTRPCContext = async () => {
   const { userId } = await auth();
-  return { userId, prisma };
+  const cookieStore = await cookies();
+  const raw = cookieStore.get("NEXT_LOCALE")?.value ?? "";
+  const locale = (LOCALES as readonly string[]).includes(raw) ? raw : defaultLocale;
+  return { userId, prisma, locale };
 };
 
 type Context = Awaited<ReturnType<typeof createTRPCContext>>;

src/trpc/routers/explore.ts

@@ -1,6 +1,7 @@
 import "server-only";
 import { z } from "zod";
 import { router, publicProcedure } from "@/trpc/init";
+import { pickLocalizedName } from "@/lib/localized-name";
 
 const TRENDING_POSTS_WINDOW_MS = 48 * 60 * 60 * 1000; // 48 h
 const TRENDING_HASHTAGS_WINDOW_MS = 7 * 24 * 60 * 60 * 1000; // 7 days
@@ -25,14 +26,20 @@ export const exploreRouter = router({
         take: input.limit + 1,
         ...(input.cursor ? { skip: 1, cursor: { id: input.cursor } } : {}),
         include: {
-          species: true,
-          breed: true,
+          species: { include: { translations: { where: { locale: ctx.locale } } } },
+          breed: { include: { translations: { where: { locale: ctx.locale } } } },
           _count: { select: { followers: true } },
         },
       });
 
       const hasNextPage = pets.length > input.limit;
-      const items = hasNextPage ? pets.slice(0, input.limit) : pets;
+      const items = (hasNextPage ? pets.slice(0, input.limit) : pets).map((pet) => ({
+        ...pet,
+        species: { ...pet.species, name: pickLocalizedName(pet.species.name, pet.species.translations, ctx.locale) },
+        breed: pet.breed
+          ? { ...pet.breed, name: pickLocalizedName(pet.breed.name, pet.breed.translations, ctx.locale) }
+          : pet.breed,
+      }));
       return {
         pets: items,
         nextCursor: hasNextPage ? items[items.length - 1]!.id : null,

src/trpc/routers/follows.ts

@@ -7,6 +7,7 @@ import { backfillOnFollow, fanOutPost } from "@/lib/feed-helpers";
 import { assertPetOwnership } from "@/lib/assert-pet-ownership";
 import { notify } from "@/lib/notify";
 import { FOLLOWER_MILESTONE_THRESHOLDS as FOLLOWER_MILESTONES } from "@/lib/milestone-thresholds";
+import { pickLocalizedName } from "@/lib/localized-name";
 
 /**
  * Follows tRPC router — pet-to-pet social graph (SOCL-01, SOCL-02, SOCL-03).
@@ -173,7 +174,7 @@ export const followsRouter = router({
               id: true,
               name: true,
               avatarKey: true,
-              species: { select: { name: true } },
+              species: { select: { name: true, translations: { where: { locale: ctx.locale } } } },
             },
           },
         },
@@ -182,7 +183,16 @@ export const followsRouter = router({
       });
 
       const hasNextPage = rows.length > input.limit;
-      const items = hasNextPage ? rows.slice(0, input.limit) : rows;
+      const items = (hasNextPage ? rows.slice(0, input.limit) : rows).map((row) => ({
+        ...row,
+        follower: {
+          ...row.follower,
+          species: {
+            ...row.follower.species,
+            name: pickLocalizedName(row.follower.species.name, row.follower.species.translations, ctx.locale),
+          },
+        },
+      }));
       const nextCursor = hasNextPage
         ? items[items.length - 1]!.createdAt.toISOString()
         : null;
@@ -241,7 +251,7 @@ export const followsRouter = router({
               id: true,
               name: true,
               avatarKey: true,
-              species: { select: { name: true } },
+              species: { select: { name: true, translations: { where: { locale: ctx.locale } } } },
             },
           },
         },
@@ -250,7 +260,16 @@ export const followsRouter = router({
       });
 
       const hasNextPage = rows.length > input.limit;
-      const items = hasNextPage ? rows.slice(0, input.limit) : rows;
+      const items = (hasNextPage ? rows.slice(0, input.limit) : rows).map((row) => ({
+        ...row,
+        followee: {
+          ...row.followee,
+          species: {
+            ...row.followee.species,
+            name: pickLocalizedName(row.followee.species.name, row.followee.species.translations, ctx.locale),
+          },
+        },
+      }));
       const nextCursor = hasNextPage
         ? items[items.length - 1]!.createdAt.toISOString()
         : null;

src/trpc/routers/pets.ts

@@ -3,6 +3,7 @@ import { TRPCError } from "@trpc/server";
 import { router, protectedProcedure } from "@/trpc/init";
 import { generateInviteCode, INVITE_CODES_PER_USER } from "@/lib/invite-codes";
 import { assertPetOwnership } from "@/lib/assert-pet-ownership";
+import { pickLocalizedName } from "@/lib/localized-name";
 
 export const petsRouter = router({
   /**
@@ -60,14 +61,21 @@ export const petsRouter = router({
    * Scoped by ownerId — never returns other owners' pets.
    */
   list: protectedProcedure.query(async ({ ctx }) => {
-    return ctx.prisma.pet.findMany({
+    const pets = await ctx.prisma.pet.findMany({
       where: { ownerId: ctx.userId },
       include: {
-        species: true,
-        breed: true,
+        species: { include: { translations: { where: { locale: ctx.locale } } } },
+        breed: { include: { translations: { where: { locale: ctx.locale } } } },
       },
       orderBy: { createdAt: "asc" },
     });
+    return pets.map((pet) => ({
+      ...pet,
+      species: { ...pet.species, name: pickLocalizedName(pet.species.name, pet.species.translations, ctx.locale) },
+      breed: pet.breed
+        ? { ...pet.breed, name: pickLocalizedName(pet.breed.name, pet.breed.translations, ctx.locale) }
+        : pet.breed,
+    }));
   }),
 
   /**
@@ -79,7 +87,10 @@ export const petsRouter = router({
     .query(async ({ ctx, input }) => {
       const pet = await ctx.prisma.pet.findUnique({
         where: { id: input.petId },
-        include: { species: true, breed: true },
+        include: {
+          species: { include: { translations: { where: { locale: ctx.locale } } } },
+          breed: { include: { translations: { where: { locale: ctx.locale } } } },
+        },
       });
 
       if (!pet || pet.ownerId !== ctx.userId) {
@@ -89,7 +100,13 @@ export const petsRouter = router({
         });
       }
 
-      return pet;
+      return {
+        ...pet,
+        species: { ...pet.species, name: pickLocalizedName(pet.species.name, pet.species.translations, ctx.locale) },
+        breed: pet.breed
+          ? { ...pet.breed, name: pickLocalizedName(pet.breed.name, pet.breed.translations, ctx.locale) }
+          : pet.breed,
+      };
     }),
 
   /**
@@ -102,10 +119,19 @@ export const petsRouter = router({
     .query(async ({ ctx, input }) => {
       const pet = await ctx.prisma.pet.findUnique({
         where: { id: input.petId },
-        include: { species: true, breed: true },
+        include: {
+          species: { include: { translations: { where: { locale: ctx.locale } } } },
+          breed: { include: { translations: { where: { locale: ctx.locale } } } },
+        },
       });
       if (!pet) throw new TRPCError({ code: "NOT_FOUND" });
-      return pet;
+      return {
+        ...pet,
+        species: { ...pet.species, name: pickLocalizedName(pet.species.name, pet.species.translations, ctx.locale) },
+        breed: pet.breed
+          ? { ...pet.breed, name: pickLocalizedName(pet.breed.name, pet.breed.translations, ctx.locale) }
+          : pet.breed,
+      };
     }),
 
   /**
@@ -144,14 +170,21 @@ export const petsRouter = router({
       if (data.adoptedAt !== undefined)
         updateData.adoptedAt = data.adoptedAt ? new Date(data.adoptedAt) : null;
 
-      return ctx.prisma.pet.update({
+      const pet = await ctx.prisma.pet.update({
         where: { id: petId },
         data: updateData,
         include: {
-          species: true,
-          breed: true,
+          species: { include: { translations: { where: { locale: ctx.locale } } } },
+          breed: { include: { translations: { where: { locale: ctx.locale } } } },
         },
       });
+      return {
+        ...pet,
+        species: { ...pet.species, name: pickLocalizedName(pet.species.name, pet.species.translations, ctx.locale) },
+        breed: pet.breed
+          ? { ...pet.breed, name: pickLocalizedName(pet.breed.name, pet.breed.translations, ctx.locale) }
+          : pet.breed,
+      };
     }),
 
   /**

src/trpc/routers/search.ts

@@ -2,6 +2,7 @@ import "server-only";
 import { z } from "zod";
 import { router, protectedProcedure } from "@/trpc/init";
 import { clerkClient } from "@clerk/nextjs/server";
+import { pickLocalizedName } from "@/lib/localized-name";
 
 export const searchRouter = router({
   pets: protectedProcedure
@@ -24,14 +25,20 @@ export const searchRouter = router({
         orderBy: { name: "asc" },
         take: input.limit + 1,
         include: {
-          species: true,
-          breed: true,
+          species: { include: { translations: { where: { locale: ctx.locale } } } },
+          breed: { include: { translations: { where: { locale: ctx.locale } } } },
           _count: { select: { followers: true } },
         },
       });
 
       const hasNextPage = pets.length > input.limit;
-      const items = hasNextPage ? pets.slice(0, input.limit) : pets;
+      const items = (hasNextPage ? pets.slice(0, input.limit) : pets).map((pet) => ({
+        ...pet,
+        species: { ...pet.species, name: pickLocalizedName(pet.species.name, pet.species.translations, ctx.locale) },
+        breed: pet.breed
+          ? { ...pet.breed, name: pickLocalizedName(pet.breed.name, pet.breed.translations, ctx.locale) }
+          : pet.breed,
+      }));
       return {
         pets: items,
         nextCursor: hasNextPage ? items[items.length - 1]!.id : null,
@@ -103,8 +110,8 @@ export const searchRouter = router({
         include: {
           pets: {
             include: {
-              species: true,
-              breed: true,
+              species: { include: { translations: { where: { locale: ctx.locale } } } },
+              breed: { include: { translations: { where: { locale: ctx.locale } } } },
               _count: { select: { followers: true } },
             },
             orderBy: { name: "asc" },
@@ -123,7 +130,13 @@ export const searchRouter = router({
               firstName: cu.firstName ?? null,
               lastName: cu.lastName ?? null,
               imageUrl: cu.imageUrl ?? null,
-              pets: owner.pets,
+              pets: owner.pets.map((pet) => ({
+                ...pet,
+                species: { ...pet.species, name: pickLocalizedName(pet.species.name, pet.species.translations, ctx.locale) },
+                breed: pet.breed
+                  ? { ...pet.breed, name: pickLocalizedName(pet.breed.name, pet.breed.translations, ctx.locale) }
+                  : pet.breed,
+              })),
             };
           }),
       };