Replace hand-written TMDB types with openapi-fetch + generated schema

- Add `openapi-fetch` dependency; generate `lib/tmdb/schema.d.ts` from
  TMDB's OpenAPI spec and delete `lib/tmdb/types.ts`
- Rewrite `lib/tmdb/client.ts` to use the typed fetch client against
  the generated schema, exporting `TmdbMovieDetails`, `TmdbTvDetails`,
  `TmdbVideo`, and `TmdbGenre` directly
- Fix null-safety across services (`credits`, `availability`,
  `metadata`, `person`, `webhooks`) and call sites (explore page,
  search route, explore actions) to handle optional fields produced
  by the stricter generated types
- Update `metadata.ts` and `metadata.test.ts` to import shared types
  from `@/lib/tmdb/client` instead of the removed `types.ts`
- Exclude `lib/tmdb/schema.d.ts` from Biome linting

app/(pages)/explore/page.tsx

@@ -16,7 +16,7 @@ function mapResults(
     media_type?: string;
     title?: string;
     name?: string;
-    poster_path: string | null;
+    poster_path?: string | null;
     release_date?: string;
     first_air_date?: string;
     vote_average: number;
@@ -31,7 +31,7 @@ function mapResults(
         ? r.media_type
         : fallbackType) as "movie" | "tv",
       title: r.title ?? r.name ?? "",
-      posterPath: tmdbImageUrl(r.poster_path, "posters"),
+      posterPath: tmdbImageUrl(r.poster_path ?? null, "posters"),
       releaseDate: r.release_date ?? r.first_air_date ?? null,
       voteAverage: r.vote_average,
     }));
@@ -49,11 +49,17 @@ async function getExploreTmdbData() {
 
   return {
     trending,
-    trendingItems: mapResults(trending.results, "movie"),
-    popularMovieItems: mapResults(popularMovies.results, "movie"),
-    popularTvItems: mapResults(popularTv.results, "tv"),
-    movieGenres: movieGenres.genres,
-    tvGenres: tvGenres.genres,
+    trendingItems: mapResults(trending.results ?? [], "movie"),
+    popularMovieItems: mapResults(popularMovies.results ?? [], "movie"),
+    popularTvItems: mapResults(popularTv.results ?? [], "tv"),
+    movieGenres: (movieGenres.genres ?? []).map((g) => ({
+      id: g.id,
+      name: g.name ?? "",
+    })),
+    tvGenres: (tvGenres.genres ?? []).map((g) => ({
+      id: g.id,
+      name: g.name ?? "",
+    })),
   };
 }
 
@@ -89,7 +95,7 @@ export default async function ExplorePage() {
     episodeProgress = getEpisodeProgressByTmdbIds(session.user.id, tmdbLookups);
   }
 
-  const heroTitle = trending.results.find(
+  const heroTitle = (trending.results ?? []).find(
     (r) =>
       r.backdrop_path && (r.media_type === "movie" || r.media_type === "tv"),
   );
@@ -100,9 +106,16 @@ export default async function ExplorePage() {
         <HeroBanner
           tmdbId={heroTitle.id}
           type={heroTitle.media_type as "movie" | "tv"}
-          title={heroTitle.title ?? heroTitle.name ?? ""}
-          overview={heroTitle.overview}
-          backdropPath={tmdbImageUrl(heroTitle.backdrop_path, "backdrops")}
+          title={
+            ("title" in heroTitle ? heroTitle.title : undefined) ??
+            ("name" in heroTitle ? heroTitle.name : undefined) ??
+            ""
+          }
+          overview={heroTitle.overview ?? ""}
+          backdropPath={tmdbImageUrl(
+            heroTitle.backdrop_path ?? null,
+            "backdrops",
+          )}
           voteAverage={heroTitle.vote_average}
         />
       )}

app/api/search/route.ts

@@ -8,7 +8,6 @@ import {
   searchTv,
 } from "@/lib/tmdb/client";
 import { tmdbImageUrl } from "@/lib/tmdb/image";
-import type { TmdbSearchResponse } from "@/lib/tmdb/types";
 
 export async function GET(req: NextRequest) {
   const session = await getSession();
@@ -51,30 +50,43 @@ export async function GET(req: NextRequest) {
     if (type === "person") {
       const personResults = await searchPerson(query);
       return NextResponse.json({
-        results: personResults.results.map((r) => ({
+        results: (personResults.results ?? []).map((r) => ({
           tmdbId: r.id,
           type: "person" as const,
           title: r.name,
-          profilePath: tmdbImageUrl(r.profile_path, "profiles"),
+          profilePath: tmdbImageUrl(r.profile_path ?? null, "profiles"),
           knownForDepartment: r.known_for_department,
           knownFor: r.known_for
             ?.slice(0, 3)
-            .map((k) => k.title ?? k.name)
+            .map((k) => k.title ?? (k as { name?: string }).name)
             .filter(Boolean),
         })),
       });
     }
 
-    let results: TmdbSearchResponse;
-    if (type === "movie") {
-      results = await searchMovies(query);
-    } else if (type === "tv") {
-      results = await searchTv(query);
-    } else {
-      results = await searchMulti(query);
-    }
+    const raw =
+      type === "movie"
+        ? await searchMovies(query)
+        : type === "tv"
+          ? await searchTv(query)
+          : await searchMulti(query);
 
-    const mapped = results.results
+    // Search endpoints return movie, TV, or multi results with slightly
+    // different fields. Widen to the union we actually access.
+    type SearchResult = {
+      id: number;
+      media_type?: string;
+      title?: string;
+      name?: string;
+      overview?: string;
+      poster_path?: string | null;
+      profile_path?: string | null;
+      release_date?: string;
+      first_air_date?: string;
+      popularity?: number;
+      vote_average?: number;
+    };
+    const mapped = ((raw.results ?? []) as SearchResult[])
       .map((r) => {
         // Include person results from multi search
         if (r.media_type === "person") {
@@ -103,7 +115,7 @@ export async function GET(req: NextRequest) {
           title: r.title ?? r.name,
           overview: r.overview,
           releaseDate: r.release_date ?? r.first_air_date,
-          posterPath: tmdbImageUrl(r.poster_path, "posters"),
+          posterPath: tmdbImageUrl(r.poster_path ?? null, "posters"),
           popularity: r.popularity,
           voteAverage: r.vote_average,
         };