Add mpv runtime dependency to installer and build scripts

INSTALLATION.md

@@ -127,6 +127,7 @@ VideoToolsClean         # Clean build artifacts and cache
 ### Essential
 - **Go 1.21 or later** - https://go.dev/dl/
 - **Bash or Zsh** shell
+- **mpv** (runtime playback backend)
 
 ### Optional
 - **FFmpeg** (for actual video encoding)
@@ -142,6 +143,20 @@ VideoToolsClean         # Clean build artifacts and cache
 ---
 
 ## Troubleshooting
+### "mpv not found"
+
+**Solution:** Install mpv from your package manager:
+
+```bash
+# Debian/Ubuntu
+sudo apt-get install -y mpv
+
+# Fedora/RHEL
+sudo dnf install -y mpv
+
+# Arch
+sudo pacman -S --needed mpv
+```
 
 ### "Go is not installed"
 
@@ -356,4 +371,3 @@ Installation works in WSL environment. Ensure you have WSL with Linux distro ins
 ---
 
 Enjoy using VideoTools! 🎬
-

scripts/build-linux.sh

@@ -42,6 +42,10 @@ fi
 if ! pkg-config --exists gl 2>/dev/null; then
     MISSING_DEPS+=("mesa-libGL-devel")
 fi
+# Runtime dependency: mpv
+if ! command -v mpv >/dev/null 2>&1; then
+    MISSING_DEPS+=("mpv")
+fi
 
 if [ ${#MISSING_DEPS[@]} -gt 0 ]; then
     echo "⚠️  Missing system dependencies: ${MISSING_DEPS[*]}"

scripts/install-deps-linux.sh

@@ -35,6 +35,7 @@ install_fedora() {
         libXxf86vm-devel \
         mesa-libGL-devel \
         alsa-lib-devel \
+        mpv \
         ffmpeg-free \
         golang
     echo "✓ Fedora dependencies installed"
@@ -55,6 +56,7 @@ install_ubuntu() {
         libxi-dev \
         libxxf86vm-dev \
         libasound2-dev \
+        mpv \
         ffmpeg \
         golang-go
     echo "✓ Ubuntu/Debian dependencies installed"
@@ -74,6 +76,7 @@ install_arch() {
         libxi \
         libxxf86vm \
         alsa-lib \
+        mpv \
         ffmpeg \
         go
     echo "✓ Arch Linux dependencies installed"
@@ -93,6 +96,7 @@ install_opensuse() {
         libXi-devel \
         libXxf86vm-devel \
         alsa-devel \
+        mpv \
         ffmpeg \
         go
     echo "✓ openSUSE dependencies installed"
@@ -158,6 +162,13 @@ else
     echo "⚠️  ffmpeg not found in PATH"
 fi
 
+# Check mpv
+if command -v mpv &> /dev/null; then
+    echo "✓ mpv: $(mpv --version | head -1)"
+else
+    echo "⚠️  mpv not found in PATH"
+fi
+
 # Check pkg-config
 if command -v pkg-config &> /dev/null; then
     echo "✓ pkg-config: $(pkg-config --version)"