Add Raspberry Pi setup script and documentation

- rpi/setup.sh: One-command install for Pi 4/5
  - Installs pyenv + Python 3.12
  - Patches and builds jpegio for ARM
  - Creates systemd service for auto-start
- rpi/README.md: Usage instructions

Install with: curl -sSL https://raw.githubusercontent.com/.../setup.sh | bash

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

rpi/README.md

@@ -0,0 +1,99 @@
+# Stegasoo Raspberry Pi
+
+Scripts and resources for deploying Stegasoo on Raspberry Pi.
+
+## Quick Install
+
+On a fresh Raspberry Pi OS (64-bit) installation:
+
+```bash
+curl -sSL https://raw.githubusercontent.com/adlee-was-taken/stegasoo/main/rpi/setup.sh | bash
+```
+
+Or download and run manually:
+
+```bash
+wget https://raw.githubusercontent.com/adlee-was-taken/stegasoo/main/rpi/setup.sh
+chmod +x setup.sh
+./setup.sh
+```
+
+## What the Setup Script Does
+
+1. **Installs system dependencies** - build tools, libraries
+2. **Installs Python 3.12** - via pyenv (Pi OS ships with 3.13 which is incompatible)
+3. **Builds jpegio for ARM** - patches x86-specific flags
+4. **Installs Stegasoo** - with web UI and all dependencies
+5. **Creates systemd service** - auto-starts on boot
+6. **Enables the service** - ready to start
+
+## Requirements
+
+- Raspberry Pi 4 or 5
+- Raspberry Pi OS (64-bit) - Bookworm or later
+- 4GB+ RAM recommended (2GB minimum)
+- ~2GB free disk space
+- Internet connection
+
+## After Installation
+
+### Start the Service
+
+```bash
+sudo systemctl start stegasoo
+```
+
+### Check Status
+
+```bash
+sudo systemctl status stegasoo
+```
+
+### View Logs
+
+```bash
+journalctl -u stegasoo -f
+```
+
+### Access Web UI
+
+Open in browser: `http://<pi-ip>:5000`
+
+On first access, you'll create an admin account.
+
+## Configuration
+
+Edit the systemd service to change settings:
+
+```bash
+sudo systemctl edit stegasoo
+```
+
+Add overrides:
+
+```ini
+[Service]
+Environment="STEGASOO_AUTH_ENABLED=true"
+Environment="STEGASOO_HTTPS_ENABLED=true"
+Environment="STEGASOO_HOSTNAME=stegasoo.local"
+```
+
+Then reload:
+
+```bash
+sudo systemctl daemon-reload
+sudo systemctl restart stegasoo
+```
+
+## Uninstall
+
+```bash
+sudo systemctl stop stegasoo
+sudo systemctl disable stegasoo
+sudo rm /etc/systemd/system/stegasoo.service
+rm -rf ~/stegasoo
+```
+
+## Pre-built Images
+
+Check [GitHub Releases](https://github.com/adlee-was-taken/stegasoo/releases) for pre-built SD card images.