chore(deps): update rpi-rgb-led-matrix install for new scikit-build-core system

The library migrated from 'make build-python' + 'pip install bindings/python'
to a scikit-build-core + cmake build where the entire repo root is pip-
installable via 'pip install .'. Update first_time_install.sh accordingly:
- Remove the 'make build-python' step (target no longer exists)
- Install directly from the repo root instead of bindings/python
- Replace build deps: remove cython3/scons/python3-dev, add python-dev-is-python3

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitmodules

@@ -1,3 +1,4 @@
 [submodule "rpi-rgb-led-matrix-master"]
 	path = rpi-rgb-led-matrix-master
 	url = https://github.com/hzeller/rpi-rgb-led-matrix.git
+	branch = master

config/config.template.json

@@ -112,7 +112,8 @@
             "limit_refresh_rate_hz": 100
         },
         "runtime": {
-            "gpio_slowdown": 3
+            "gpio_slowdown": 3,
+            "rp1_rio": 0
         },
         "display_durations": {},
         "use_short_date_format": true,

first_time_install.sh

@@ -271,7 +271,7 @@ apt_update
 
 # Install required system packages
 echo "Installing Python packages and dependencies..."
-apt_install python3-pip python3-venv python3-dev python3-pil python3-pil.imagetk build-essential python3-setuptools python3-wheel cython3 scons cmake ninja-build
+apt_install python3-pip python3-venv python-dev-is-python3 python3-pil python3-pil.imagetk build-essential python3-setuptools python3-wheel cmake ninja-build
 
 # Install additional system dependencies that might be needed
 echo "Installing additional system dependencies..."
@@ -795,7 +795,7 @@ else
         # Try to initialize submodule if .gitmodules exists
         if [ -f "$PROJECT_ROOT_DIR/.gitmodules" ] && grep -q "rpi-rgb-led-matrix" "$PROJECT_ROOT_DIR/.gitmodules"; then
             echo "Initializing rpi-rgb-led-matrix submodule..."
-            if ! git submodule update --init --recursive rpi-rgb-led-matrix-master 2>&1; then
+            if ! git submodule update --init --remote --recursive rpi-rgb-led-matrix-master 2>&1; then
                 echo "⚠ Submodule init failed, cloning directly from GitHub..."
                 git clone https://github.com/hzeller/rpi-rgb-led-matrix.git rpi-rgb-led-matrix-master
             fi
@@ -814,27 +814,20 @@ else
             cd "$PROJECT_ROOT_DIR"
             rm -rf rpi-rgb-led-matrix-master
             if [ -f "$PROJECT_ROOT_DIR/.gitmodules" ] && grep -q "rpi-rgb-led-matrix" "$PROJECT_ROOT_DIR/.gitmodules"; then
-                git submodule update --init --recursive rpi-rgb-led-matrix-master
+                git submodule update --init --remote --recursive rpi-rgb-led-matrix-master
             else
                 git clone https://github.com/hzeller/rpi-rgb-led-matrix.git rpi-rgb-led-matrix-master
             fi
         fi
         
         pushd "$PROJECT_ROOT_DIR/rpi-rgb-led-matrix-master" >/dev/null
-        echo "Building rpi-rgb-led-matrix Python bindings..."
-        # Build the library first, then Python bindings
-        # The build-python target depends on the library being built
-        if ! make build-python; then
-            echo "✗ Failed to build rpi-rgb-led-matrix Python bindings"
-            echo "  Make sure you have the required build tools installed:"
-            echo "  sudo apt install -y build-essential python3-dev cython3 scons"
-            popd >/dev/null
-            exit 1
-        fi
-        cd bindings/python
-        echo "Installing rpi-rgb-led-matrix Python package via pip..."
+        echo "Installing rpi-rgb-led-matrix Python package (scikit-build-core + cmake)..."
+        echo "  Build deps required: python-dev-is-python3 cmake"
+        echo "  This compiles C++ — may take 2-5 minutes on Pi 4/5..."
         if ! python3 -m pip install --break-system-packages .; then
             echo "✗ Failed to install rpi-rgb-led-matrix Python package"
+            echo "  Ensure build tools are installed:"
+            echo "  sudo apt install -y python-dev-is-python3 cmake build-essential"
             popd >/dev/null
             exit 1
         fi

src/display_manager.py

@@ -100,6 +100,10 @@ class DisplayManager:
                 options.pwm_dither_bits = hardware_config.get('pwm_dither_bits')
             if 'inverse_colors' in hardware_config:
                 options.inverse_colors = hardware_config.get('inverse_colors')
+            # Pi 5 only: 0=PIO/RP1 coprocessor (default, less CPU),
+            # 1=RIO/Registered IO (faster; gpio_slowdown effect is inverted in this mode)
+            if 'rp1_rio' in runtime_config:
+                options.rp1_rio = runtime_config.get('rp1_rio')
             
             logger.info(f"Initializing RGB Matrix with settings: rows={options.rows}, cols={options.cols}, chain_length={options.chain_length}, parallel={options.parallel}, hardware_mapping={options.hardware_mapping}")