Förslagsmotorn: Generera-knapp, schema, diskcache och bläddringssida

- suggest.js: samlar signaler (Lidarr-bibliotek, Jellyfin senast spelat,
  Youtubarr-DB senast tillagt/gillat via better-sqlite3 ro), bygger svensk
  Gemini-prompt (JSON-svar), berikar förslagen med MBID/omslag via Lidarrs
  metadata-API, cachar batcher i /data/suggestions.json
- API: POST /api/suggest/run, GET latest (10 senaste till Upptäck),
  GET batches + batches/:id (bläddring)
- Schemaläggare i server.js: kollar var 10:e minut mot inställningen
  suggest.intervalHours (default 24, 0 = av) — ställs in under ⚙
- Upptäck: senaste 10 som kort med motivering + '✨ Generera nya förslag';
  ny Förslag-sida bläddrar alla cachade batcher; delat MusicCard-kort
  (sök + förslag) med Hämta-knapp
- Dockerfile: byggverktyg för better-sqlite3; 4 nya tester, totalt 25

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01824ZrvG2mDYYrmwqypLNup

backend/test/suggest.test.js

@@ -0,0 +1,117 @@
+import test from 'node:test'
+import assert from 'node:assert/strict'
+import { existsSync, mkdtempSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import path from 'node:path'
+import Database from 'better-sqlite3'
+import { settingsStore } from '../src/settings.js'
+import { suggestEngine } from '../src/suggest.js'
+
+function makeYoutubarrDb(dir) {
+  const p = path.join(dir, 'db.sqlite3')
+  const db = new Database(p)
+  db.exec(`
+    CREATE TABLE youtubarr_playlist (id INTEGER PRIMARY KEY, title TEXT);
+    CREATE TABLE youtubarr_trackitem (
+      id INTEGER PRIMARY KEY, playlist_id INTEGER, title TEXT,
+      artist_name_guess TEXT, blacklisted INTEGER DEFAULT 0
+    );
+    INSERT INTO youtubarr_playlist VALUES (1, 'lefu-Musick');
+    INSERT INTO youtubarr_trackitem VALUES (1, 1, 'Amaranth', 'Nightwish', 0);
+    INSERT INTO youtubarr_trackitem VALUES (2, 1, 'Svart', 'Hemligt Band', 1);
+  `)
+  db.close()
+  return p
+}
+
+function setup({ geminiResponse } = {}) {
+  const dataDir = mkdtempSync(path.join(tmpdir(), 'lyssnarr-sug-'))
+  const ytDir = mkdtempSync(path.join(tmpdir(), 'lyssnarr-ytdb-'))
+  const store = settingsStore(dataDir)
+  store.save({ gemini: { apiKey: 'g-nyckel' }, jellyfin: { apiKey: 'jf', userId: 'u1' } })
+  const config = {
+    dataDir,
+    gemini: { apiKey: '', model: 'gemini-2.5-flash' },
+    jellyfin: { url: 'http://jellyfin:8096', apiKey: '' },
+    youtubarr: { dbPath: makeYoutubarrDb(ytDir), dataDir: ytDir },
+  }
+  const lidarr = {
+    artists: async () => [{ artistName: 'Powerwolf' }],
+    search: async () => [
+      {
+        artist: {
+          foreignArtistId: 'mbid-x',
+          artistName: 'Sabaton',
+          images: [{ coverType: 'poster', remoteUrl: 'http://img/s.jpg' }],
+        },
+      },
+    ],
+  }
+  const calls = []
+  const fetchImpl = async (url, opts) => {
+    calls.push(url)
+    if (url.includes('generativelanguage')) {
+      const body = JSON.parse(opts.body)
+      fetchImpl.prompt = body.contents[0].parts[0].text
+      return {
+        ok: true,
+        json: async () => ({
+          candidates: [{ content: { parts: [{ text: geminiResponse ?? JSON.stringify([
+            { type: 'artist', name: 'Sabaton', motivation: 'Powermetal som Powerwolf.' },
+          ]) }] } }],
+        }),
+      }
+    }
+    if (url.includes('/Users/u1/Items')) {
+      return { ok: true, json: async () => ({ Items: [{ Name: 'Zenit', Artists: ['1000mods'] }] }) }
+    }
+    throw new Error('oväntad url: ' + url)
+  }
+  const engine = suggestEngine({ config, store, lidarr, fetchImpl })
+  return { engine, fetchImpl, dataDir }
+}
+
+test('run: samlar signaler, frågar Gemini, berikar och cachar på disk', async () => {
+  const { engine, fetchImpl, dataDir } = setup()
+  const batch = await engine.run('manuell')
+
+  assert.match(fetchImpl.prompt, /Powerwolf/, 'biblioteket ska in i prompten')
+  assert.match(fetchImpl.prompt, /1000mods – Zenit/, 'jellyfin-historiken ska in i prompten')
+  assert.match(fetchImpl.prompt, /Nightwish – Amaranth \[lefu-Musick\]/, 'YT-tillägg ska in i prompten')
+  assert.ok(!fetchImpl.prompt.includes('Hemligt Band'), 'svartlistade låtar ska inte med')
+
+  assert.equal(batch.items.length, 1)
+  const item = batch.items[0]
+  assert.equal(item.name, 'Sabaton')
+  assert.equal(item.mbid, 'mbid-x')
+  assert.equal(item.poster, 'http://img/s.jpg')
+  assert.equal(item.motivation, 'Powermetal som Powerwolf.')
+
+  assert.ok(existsSync(path.join(dataDir, 'suggestions.json')))
+  assert.equal(engine.latest(10).length, 1)
+  assert.equal(engine.lastRun(), batch.createdAt)
+})
+
+test('run: batch-id räknas upp och latest tar nyaste först', async () => {
+  const { engine } = setup()
+  const b1 = await engine.run()
+  const b2 = await engine.run()
+  assert.equal(b2.id, b1.id + 1)
+  assert.equal(engine.loadBatches().length, 2)
+  assert.equal(engine.loadBatches()[0].id, b2.id)
+})
+
+test('run: markdown-staket runt JSON hanteras', async () => {
+  const { engine } = setup({
+    geminiResponse: '```json\n[{"type":"artist","name":"Ghost","motivation":"x"}]\n```',
+  })
+  const batch = await engine.run()
+  assert.equal(batch.items[0].name, 'Ghost')
+})
+
+test('run utan Gemini-nyckel ger begripligt fel', async () => {
+  const { engine, dataDir } = setup()
+  const store = settingsStore(dataDir)
+  store.save({ gemini: { apiKey: '' } })
+  await assert.rejects(() => engine.run(), /Gemini-nyckel saknas/)
+})