Switch mods to per-folder auto-discovery and resourcepack to single zip

- PackDefinition: replace mods[]/resourcepacks[] with modsFolder (string) + resourcepackPath (string); drop PackAsset
- Editor: replace dynamic add/remove lists with two single inputs; remove the now-dead JS for adding/removing rows
- Server: expose GET /file/mods/<folder>/index.json that returns the list of .jar names; folder name restricted to [a-zA-Z0-9_-]+
- Installer: fetch the listing JSON and download each jar from /file/mods/<folder>/<file>.jar; download the single resourcepack from /file/resourcepacks/<file>.zip directly into resourcepacks/

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/installer/main.ts

@@ -246,6 +246,43 @@ async function downloadMapZip(pack: PackDefinition, customRoot: string): Promise
   await downloadAndExtractZip(url, '맵', savesDir)
 }
 
+async function downloadModsFolder(pack: PackDefinition, customRoot: string): Promise<void> {
+  if (!pack.modsFolder) {
+    sendLog('modsFolder가 비어 있어 모드 다운로드를 건너뜁니다.')
+    return
+  }
+  const indexUrl = `${state.baseUrl}/file/mods/${encodeURIComponent(pack.modsFolder)}/index.json`
+  sendLog(`모드 목록 조회: ${indexUrl}`)
+  const listing = await fetchJson<{ files?: unknown }>(indexUrl)
+  const files = Array.isArray(listing.files)
+    ? listing.files.filter((name): name is string => typeof name === 'string' && /\.jar$/i.test(name))
+    : []
+  if (files.length === 0) {
+    sendLog(`/file/mods/${pack.modsFolder}/ 안에 .jar 파일이 없습니다.`)
+    return
+  }
+  const modsDir = path.join(customRoot, 'mods')
+  await fsp.mkdir(modsDir, { recursive: true })
+  for (const fileName of files) {
+    const url = `${state.baseUrl}/file/mods/${encodeURIComponent(pack.modsFolder)}/${encodeURIComponent(fileName)}`
+    const target = path.join(modsDir, fileName)
+    sendLog(`모드 다운로드: ${fileName}`)
+    await downloadFile(url, target)
+  }
+}
+
+async function downloadResourcepackZip(pack: PackDefinition, customRoot: string): Promise<void> {
+  if (!pack.resourcepackPath) {
+    sendLog('resourcepackPath가 비어 있어 리소스팩 다운로드를 건너뜁니다.')
+    return
+  }
+  const url = `${state.baseUrl}/file/resourcepacks/${pack.resourcepackPath.replace(/^\/+/, '')}`
+  const target = path.join(customRoot, 'resourcepacks', pack.resourcepackPath.replace(/^\/+/, ''))
+  await fsp.mkdir(path.dirname(target), { recursive: true })
+  sendLog(`리소스팩 다운로드: ${url}`)
+  await downloadFile(url, target)
+}
+
 ipcMain.handle('server:install', async (_event, payload: ServerInstallPayload) => {
   const pack = state.packs.get(payload.packKey)
   if (!pack) throw new Error('음악퀴즈를 찾을 수 없습니다.')
@@ -496,18 +533,8 @@ ipcMain.handle('client:install', async (_event, payload: ClientInstallPayload) =
     sendLog('플랫폼 설치 건너뜀. 바닐라로 진행합니다.')
   }
 
-  for (const mod of pack.pack.mods) {
-    if (!mod.downloadUrl) continue
-    const target = path.join(customRoot, 'mods', deriveFileName(mod.downloadUrl) || `${mod.name}.jar`)
-    sendLog(`모드 다운로드: ${mod.name}`)
-    await downloadFile(mod.downloadUrl, target)
-  }
-  for (const resourcePack of pack.pack.resourcepacks) {
-    if (!resourcePack.downloadUrl) continue
-    const target = path.join(customRoot, 'resourcepacks', deriveFileName(resourcePack.downloadUrl) || `${resourcePack.name}.zip`)
-    sendLog(`리소스팩 다운로드: ${resourcePack.name}`)
-    await downloadFile(resourcePack.downloadUrl, target)
-  }
+  await downloadModsFolder(pack.pack, customRoot)
+  await downloadResourcepackZip(pack.pack, customRoot)
 
   await downloadMapZip(pack.pack, customRoot)