feat(web): MB-resolve manual imports for instant cover art

A manually-imported album had no release-group MBID, so it showed the ◉
placeholder until a Scan matched it. Now the import resolves the release group
(searchReleaseGroup, via the shared MB cache) and stores it on the new
LibraryItem.rgMbid column (migration add_library_rg_mbid). The library route
prefers LibraryItem.rgMbid, falling back to the MonitoredRelease join for
scanned items — so a manual album gets cover art immediately. Best-effort: a
no-match / MB outage just leaves rgMbid null.

web 164 tests, tsc + build clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/app/api/library/import/route.test.ts

@@ -1,4 +1,5 @@
-import { describe, it, expect, beforeEach, afterEach } from "vitest";
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+vi.mock("@/lib/musicbrainz", () => ({ searchReleaseGroup: vi.fn(async () => null) }));
 import { mkdtempSync, existsSync, readFileSync, readdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";

web/src/app/api/library/import/route.ts

@@ -7,6 +7,7 @@ import { randomUUID } from "node:crypto";
 import Busboy from "busboy";
 import { prisma } from "@/lib/db";
 import { isAuthed } from "@/lib/auth";
+import { searchReleaseGroup } from "@/lib/musicbrainz";
 
 // Manually import an album (a ripped CD / files already on the PC): upload the audio (+ an
 // optional cover) with artist/album/year, and Lyra writes it into the library. The web
@@ -104,6 +105,15 @@ export async function POST(request: Request) {
   await mkdir(dirname(finalDir), { recursive: true });
   await rename(staging, finalDir);
 
+  // Resolve the release group so the album gets cover art immediately (best-effort — a
+  // no-match just leaves rgMbid null; a later Scan can still match it). Uses the shared MB cache.
+  let rgMbid: string | null = null;
+  try {
+    rgMbid = (await searchReleaseGroup(artist, album))?.rgMbid ?? null;
+  } catch {
+    /* MB unavailable — carry on without cover art */
+  }
+
   const firstExt = extname(audio[0]).toLowerCase();
   await prisma.libraryItem.create({
     data: {
@@ -115,6 +125,7 @@ export async function POST(request: Request) {
       // rough class from the extension (2 = CD-lossless, 1 = lossy); a later scan re-probes and
       // can upgrade a hi-res file to class 3.
       qualityClass: LOSSLESS_EXT.has(firstExt) ? 2 : 1,
+      rgMbid,
       trackNames: audio,
     },
   });