Add RPi install docs, GHCR support, push-docker-all script

- README: Raspberry Pi install section with auto-detect architecture
- README: pre-built binary download section for all platforms
- Docker docs: dual registry (Gitea + GHCR)
- scripts/push-docker-all.sh: push to both registries in one command

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

README.md

@@ -42,14 +42,51 @@ On wired gigabit links, expect line-rate performance in both TCP and UDP modes.
 cargo install --path .
 ```
 
-### Pre-built binary (Linux x86_64)
+### Pre-built binaries
+
+Download from [releases](https://git.manko.yoga/manawenuz/btest-rs/releases) or [GitHub releases](https://github.com/manawenuz/btest-rs/releases):
 
 ```bash
-# Cross-compile from macOS (requires Docker)
-scripts/build-linux.sh
+# Linux x86_64
+curl -L <release-url>/btest-linux-x86_64.tar.gz | tar xz
+sudo mv btest /usr/local/bin/
 
-# Copy to server
-scp dist/btest root@yourserver:/usr/local/bin/btest
+# Raspberry Pi 4/5 (64-bit OS)
+curl -L <release-url>/btest-linux-aarch64.tar.gz | tar xz
+sudo mv btest /usr/local/bin/
+
+# Raspberry Pi 3/Zero 2 (32-bit OS)
+curl -L <release-url>/btest-linux-armv7.tar.gz | tar xz
+sudo mv btest /usr/local/bin/
+
+# Windows
+# Download btest-windows-x86_64.zip from releases
+```
+
+### Raspberry Pi
+
+The static musl binaries run on any Raspberry Pi without dependencies:
+
+```bash
+# On the Pi — detect architecture and install
+ARCH=$(uname -m)
+case $ARCH in
+  aarch64) FILE=btest-linux-aarch64.tar.gz ;;
+  armv7l)  FILE=btest-linux-armv7.tar.gz ;;
+  *)       echo "Unsupported: $ARCH"; exit 1 ;;
+esac
+
+curl -LO "https://github.com/manawenuz/btest-rs/releases/latest/download/$FILE"
+tar xzf "$FILE"
+sudo mv btest /usr/local/bin/
+rm "$FILE"
+
+# Run as server
+btest -s -a admin -p password --ecsrp5
+
+# Or install as systemd service
+curl -LO https://raw.githubusercontent.com/manawenuz/btest-rs/main/scripts/install-service.sh
+sudo bash install-service.sh --auth-user admin --auth-pass password
 ```
 
 ### Docker

docs/docker.md

@@ -1,11 +1,12 @@
 # Docker and Deployment Guide
 
-## Container Registry
+## Container Registries
 
 Images are published to:
 
 ```
-git.manko.yoga/manawenuz/btest-rs
+git.manko.yoga/manawenuz/btest-rs    # Gitea registry
+ghcr.io/manawenuz/btest-rs           # GitHub Container Registry
 ```
 
 ## Quick Start

scripts/push-docker-all.sh

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+# Build and push Docker image to both Gitea and GitHub Container Registry.
+#
+# Prerequisites:
+#   docker login git.manko.yoga        (Gitea — your username + token)
+#   docker login ghcr.io               (GitHub — your username + PAT with packages:write)
+#
+# Usage:
+#   ./scripts/push-docker-all.sh v0.6.0
+set -euo pipefail
+
+cd "$(dirname "$0")/.."
+
+if [[ -f .env ]]; then
+    set -a; source .env; set +a
+fi
+
+TAG="${1:?Usage: $0 <tag> (e.g. v0.6.0)}"
+
+GITEA_IMAGE="git.manko.yoga/manawenuz/btest-rs"
+GHCR_IMAGE="ghcr.io/manawenuz/btest-rs"
+
+echo "=== Building Docker image ==="
+docker build \
+    -t "${GITEA_IMAGE}:${TAG}" \
+    -t "${GITEA_IMAGE}:latest" \
+    -t "${GHCR_IMAGE}:${TAG}" \
+    -t "${GHCR_IMAGE}:latest" \
+    .
+
+echo ""
+echo "=== Pushing to Gitea ==="
+docker push "${GITEA_IMAGE}:${TAG}"
+docker push "${GITEA_IMAGE}:latest"
+
+echo ""
+echo "=== Pushing to GitHub Container Registry ==="
+docker push "${GHCR_IMAGE}:${TAG}"
+docker push "${GHCR_IMAGE}:latest"
+
+echo ""
+echo "Done! Images pushed:"
+echo "  ${GITEA_IMAGE}:${TAG}"
+echo "  ${GITEA_IMAGE}:latest"
+echo "  ${GHCR_IMAGE}:${TAG}"
+echo "  ${GHCR_IMAGE}:latest"
+echo ""
+echo "Pull with:"
+echo "  docker pull ${GHCR_IMAGE}:${TAG}"
+echo "  docker run --rm -p 2000:2000 -p 2001-2100:2001-2100/udp ${GHCR_IMAGE}:${TAG} -s -v"