installer: write custom icon into Minecraft launcher profile

Minecraft launcher's "설치 설정" screen reads `profile.icon` from
launcher_profiles.json. We were leaving it unset, so the launcher fell
back to the default Furnace icon. Inline build/icon.png as a base64
data URL at build time (scripts/build-launcher-icon.cjs generates
src/installer/launcherIcon.ts) and set it on the profile we write.

The build/ directory isn't included in the electron-builder asar (it's
only used to point at the .ico for the exe), so a runtime read isn't
possible — the icon ships compiled into the bundle. To refresh after
changing icon.png, run `npm run build:launcher-icon` (it's wired into
`dist:win` so a fresh exe build always regenerates it).

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "minecraft-music-quiz-installer",
-  "version": "0.2.5",
+  "version": "0.2.6",
   "description": "마인크래프트 음악퀴즈 간편설치기 + 관리 사이트",
   "main": "dist/installer/main.js",
   "scripts": {
@@ -10,7 +10,8 @@
     "installer": "tsc -p tsconfig.installer.json && electron .",
     "installer:rp": "tsc -p tsconfig.installer-rp.json && electron dist/installer-rp/main.js",
     "preinstall:sharp-win32": "npm install --no-save --force @img/sharp-win32-x64@0.34.5",
-    "dist:win": "npm run preinstall:sharp-win32 && tsc -p tsconfig.installer.json && electron-builder --win --config electron-builder.yml",
+    "build:launcher-icon": "node scripts/build-launcher-icon.cjs",
+    "dist:win": "npm run preinstall:sharp-win32 && npm run build:launcher-icon && tsc -p tsconfig.installer.json && electron-builder --win --config electron-builder.yml",
     "dist:win:rp": "npm run preinstall:sharp-win32 && tsc -p tsconfig.installer-rp.json && electron-builder --win --config electron-builder-rp.yml"
   },
   "dependencies": {

scripts/build-launcher-icon.cjs

@@ -0,0 +1,33 @@
+#!/usr/bin/env node
+// build/icon.png 을 읽어 base64 data URL 로 변환해
+// src/installer/launcherIcon.ts 에 상수로 박는다.
+//
+// 마인크래프트 런처의 "설치 설정" 화면 프로필 아이콘은
+// launcher_profiles.json 의 profile.icon 필드에서 오는데,
+// `data:image/png;base64,...` 형태의 data URL 을 받는다.
+// build/ 폴더는 electron-builder 가 exe 아이콘으로만 쓰고 asar 에
+// 포함되지 않아서, 런타임에 그 파일을 읽을 수 없다. 대신 빌드(개발) 시점에
+// 이 스크립트를 돌려 PNG 를 소스 코드에 인라인한다.
+
+'use strict'
+
+const fs = require('node:fs')
+const path = require('node:path')
+
+const repoRoot = path.resolve(__dirname, '..')
+const pngPath = path.join(repoRoot, 'build', 'icon.png')
+const tsPath = path.join(repoRoot, 'src', 'installer', 'launcherIcon.ts')
+
+const buf = fs.readFileSync(pngPath)
+const b64 = buf.toString('base64')
+
+const ts = `// AUTO-GENERATED by scripts/build-launcher-icon.cjs from build/icon.png.
+// 마인크래프트 런처의 "설치 설정" 화면에서 보이는 프로필 아이콘. exe 와 같은
+// 이미지를 쓰기 위해 빌드 시점에 PNG 를 data URL 로 인라인한다. 변경하려면
+// build/icon.png 교체 후 \`node scripts/build-launcher-icon.cjs\` 재실행.
+export const LAUNCHER_PROFILE_ICON =
+  'data:image/png;base64,${b64}'
+`
+
+fs.writeFileSync(tsPath, ts, 'utf8')
+console.log(`wrote ${tsPath} (${buf.length} bytes PNG → ${b64.length} chars base64)`)

src/installer/main.ts

@@ -22,6 +22,7 @@ import type { Manifest, PackDefinition } from '../shared/types.js'
 import { normalizePackDefinition } from '../shared/store.js'
 import { loadEnv, getManifestUrl } from '../shared/env.js'
 import { loadComponentI18n } from '../shared/i18n.js'
+import { LAUNCHER_PROFILE_ICON } from './launcherIcon.js'
 
 loadEnv()
 
@@ -1469,6 +1470,7 @@ async function updateLauncherProfile(pack: PackDefinition, gameDir: string): Pro
     ...existingProfile,
     name: profileKey,
     type: 'custom',
+    icon: LAUNCHER_PROFILE_ICON,
     gameDir,
     lastVersionId,
     javaArgs