Add PiCam network streamer with auto-setup for Pi 5

Initial commit of the MJPEG streaming server for Raspberry Pi.
Supports Pi Camera Module (via picamera2), USB webcams (via OpenCV),
and auto-detection of camera type.

Includes:
- `stream_picamera2.py` — optimized Pi CSI camera streamer
- `stream_usb.py` — generic USB camera streamer
- `stream.py` — auto-detects camera and launches correct streamer
- `image-setup/` — SD card imaging scripts and Pi 5 headless setup
  guide for first-boot automation with systemd service
- `requirements.txt` — Python dependencies

image-setup/firstrun.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+# Raspberry Pi First-Boot Script
+# Place this file on the bootfs partition as 'firstrun.sh' to execute on first boot.
+# It will trigger the autosetup.sh script located in /boot/autosetup.sh
+
+BOOT_SCRIPT="/boot/firmware/autosetup.sh"
+
+# For older Raspberry Pi OS versions, the boot partition is mounted at /boot
+if [ ! -f "$BOOT_SCRIPT" ]; then
+    BOOT_SCRIPT="/boot/autosetup.sh"
+fi
+
+if [ -f "$BOOT_SCRIPT" ]; then
+    echo "Found autosetup script at $BOOT_SCRIPT"
+    chmod +x "$BOOT_SCRIPT"
+    # Run as the default user (usually pi)
+    sudo -u pi bash "$BOOT_SCRIPT"
+else
+    echo "No autosetup.sh found on boot partition."
+fi