Replace search page with explore page for rich discovery experience

The command palette (⌘K) already handles direct title search. Replace the
redundant /search page with a new /explore page featuring trending titles,
popular movies/TV, and genre browsing powered by TMDB discovery endpoints.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/api/explore/discover/route.ts

@@ -0,0 +1,48 @@
+import { type NextRequest, NextResponse } from "next/server";
+import { isTmdbConfigured } from "@/lib/config";
+import { discover } from "@/lib/tmdb/client";
+
+export async function GET(req: NextRequest) {
+  if (!isTmdbConfigured()) {
+    return NextResponse.json(
+      {
+        error: "TMDB API key is not configured. Visit /setup for instructions.",
+        code: "TMDB_NOT_CONFIGURED",
+      },
+      { status: 503 },
+    );
+  }
+
+  const { searchParams } = req.nextUrl;
+  const type = searchParams.get("type") === "tv" ? "tv" : "movie";
+  const genre = searchParams.get("genre");
+  const sortBy = searchParams.get("sort_by") || "popularity.desc";
+  const page = searchParams.get("page") || "1";
+
+  const params: Record<string, string> = {
+    sort_by: sortBy,
+    "vote_count.gte": "50",
+  };
+  if (genre) {
+    params.with_genres = genre;
+  }
+
+  const results = await discover(type, params, Number(page));
+
+  const filtered = results.results.filter((r) => r.poster_path);
+
+  return NextResponse.json({
+    results: filtered.map((r) => ({
+      tmdbId: r.id,
+      type,
+      title: r.title ?? r.name,
+      overview: r.overview,
+      releaseDate: r.release_date ?? r.first_air_date,
+      posterPath: r.poster_path,
+      popularity: r.popularity,
+      voteAverage: r.vote_average,
+    })),
+    page: results.page,
+    totalPages: results.total_pages,
+  });
+}