feat: bundle FFmpeg via ffmpeg-static for one-click deployment

Users no longer need to install FFmpeg separately — it is now bundled as
an npm dependency (ffmpeg-static). player.ts resolves the bundled binary
automatically and falls back to system PATH. start.bat and a new
setup.bat script handle dependency installation and project building.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/setup.bat

@@ -0,0 +1,91 @@
+@echo off
+title TSMusicBot Setup
+echo ============================================
+echo   TSMusicBot - First-Time Setup (Windows)
+echo ============================================
+echo.
+
+:: Resolve project root (one level up from scripts/)
+cd /d "%~dp0.."
+
+:: ---- Step 1: Check / install Node.js ----
+where node >nul 2>&1
+if %errorlevel% neq 0 (
+    echo Node.js not found. Attempting automatic installation...
+    echo.
+
+    :: Try winget first (available on Windows 10 1709+ and Windows 11)
+    where winget >nul 2>&1
+    if %errorlevel% equ 0 (
+        echo Installing Node.js via winget...
+        winget install OpenJS.NodeJS.LTS --accept-source-agreements --accept-package-agreements
+        if %errorlevel% neq 0 (
+            echo winget installation failed. Please install Node.js manually from https://nodejs.org
+            pause
+            exit /b 1
+        )
+        :: Refresh PATH so node is available in this session
+        call refreshenv >nul 2>&1
+        :: If refreshenv is not available, ask user to restart
+        where node >nul 2>&1
+        if %errorlevel% neq 0 (
+            echo.
+            echo Node.js was installed but is not yet available in this terminal.
+            echo Please close this window and run setup.bat again.
+            pause
+            exit /b 0
+        )
+    ) else (
+        echo winget is not available on this system.
+        echo Please install Node.js 20 LTS manually from https://nodejs.org
+        echo After installing, close this window and run setup.bat again.
+        pause
+        exit /b 1
+    )
+) else (
+    echo [OK] Node.js found.
+    node --version
+)
+echo.
+
+:: ---- Step 2: Install npm dependencies ----
+echo Installing dependencies (this may take a few minutes)...
+call npm install
+if %errorlevel% neq 0 (
+    echo.
+    echo npm install failed. Check the error messages above.
+    pause
+    exit /b 1
+)
+echo [OK] Dependencies installed.
+echo.
+
+:: ---- Step 3: Build the project ----
+echo Building TypeScript project...
+call npx tsc
+if %errorlevel% neq 0 (
+    echo.
+    echo Build failed. Check the error messages above.
+    pause
+    exit /b 1
+)
+echo [OK] Build succeeded.
+echo.
+
+:: ---- Step 4: Create default config if missing ----
+if not exist "config.json" (
+    echo Creating default config.json...
+    echo Please edit config.json with your TeamSpeak server details before starting the bot.
+) else (
+    echo [OK] config.json already exists.
+)
+echo.
+
+:: ---- Done ----
+echo ============================================
+echo   Setup complete!
+echo ============================================
+echo.
+echo To start the bot, run:  scripts\start.bat
+echo.
+pause