feat(scripts): add one-line install script

- Add `scripts/install.sh` — a single `curl | bash` installer that handles system deps, Rust, clone, build, and install
  automatically.
- Update README Linux/macOS section with a "One-Line Installer (Recommended)" block above the existing manual steps.

1. Detects OS (Linux apt/dnf, macOS Xcode CLT)
2. Installs build deps + git via system package manager (sudo only here)
3. Installs Rust via rustup (skipped if already present)
4. Shallow-clones the repo to `/tmp/zeroclaw-install`
5. `cargo build --release --locked` + `cargo install --path . --force --locked`
6. Cleans up temp dir and prints next steps (`source ~/.cargo/env`, `zeroclaw onboard`)

scripts/installer.sh

@@ -0,0 +1,151 @@
+#!/usr/bin/env bash
+# install.sh — Build and install ZeroClaw from source.
+# Usage:
+#   curl -LsSf https://raw.githubusercontent.com/zeroclaw-labs/zeroclaw/main/scripts/install.sh | bash
+#   # or
+#   bash scripts/install.sh
+
+set -euo pipefail
+
+# --- Logging --------------------------------------------------------------
+
+info()  { printf ">>> %s\n" "$*"; }
+warn()  { printf ">>> [WARN] %s\n" "$*"; }
+error() { printf ">>> [ERROR] %s\n" "$*" >&2; }
+die()   { error "$@"; exit 1; }
+
+# --- Step 1: Detect OS and install system dependencies --------------------
+
+install_system_deps() {
+    info "Detecting operating system..."
+
+    local os
+    os="$(uname -s)"
+
+    case "${os}" in
+        Linux)
+            install_linux_deps
+            ;;
+        Darwin)
+            install_macos_deps
+            ;;
+        *)
+            die "Unsupported operating system: ${os}. Only Linux and macOS are supported."
+            ;;
+    esac
+}
+
+install_linux_deps() {
+    if command -v apt-get >/dev/null 2>&1; then
+        info "Detected Debian/Ubuntu — installing build-essential, pkg-config, git..."
+        sudo apt-get update -qq
+        sudo apt-get install -y build-essential pkg-config git
+    elif command -v dnf >/dev/null 2>&1; then
+        info "Detected Fedora/RHEL — installing Development Tools, pkg-config, git..."
+        sudo dnf groupinstall -y "Development Tools"
+        sudo dnf install -y pkg-config git
+    else
+        die "Unsupported Linux distribution. Please install a C compiler, pkg-config, and git manually, then re-run this script."
+    fi
+}
+
+install_macos_deps() {
+    if ! xcode-select -p >/dev/null 2>&1; then
+        info "Installing Xcode Command Line Tools..."
+        xcode-select --install
+        warn "A dialog may have appeared. Please complete the Xcode CLT installation, then re-run this script."
+        exit 0
+    else
+        info "Xcode Command Line Tools already installed."
+    fi
+
+    if ! command -v git >/dev/null 2>&1; then
+        die "git not found. Please install git (e.g. via Homebrew) and re-run this script."
+    fi
+}
+
+# --- Step 2: Install Rust -------------------------------------------------
+
+install_rust() {
+    if command -v rustc >/dev/null 2>&1; then
+        info "Rust already installed ($(rustc --version))."
+    else
+        info "Installing Rust via rustup..."
+        curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+        # shellcheck source=/dev/null
+        source "${HOME}/.cargo/env"
+        info "Rust installed ($(rustc --version))."
+    fi
+}
+
+# --- Step 3: Clone repository ---------------------------------------------
+
+CLONE_DIR="/tmp/zeroclaw-install"
+
+clone_repo() {
+    if [ -d "${CLONE_DIR}" ]; then
+        info "Removing previous clone at ${CLONE_DIR}..."
+        rm -rf "${CLONE_DIR}"
+    fi
+
+    info "Cloning ZeroClaw repository..."
+    git clone --depth 1 https://github.com/zeroclaw-labs/zeroclaw.git "${CLONE_DIR}"
+}
+
+# --- Step 4: Build and install --------------------------------------------
+
+build_and_install() {
+    info "Building ZeroClaw (release mode)..."
+    cargo build --release --locked --manifest-path "${CLONE_DIR}/Cargo.toml"
+
+    info "Installing ZeroClaw binary..."
+    cargo install --path "${CLONE_DIR}" --force --locked
+}
+
+# --- Step 5: Cleanup ------------------------------------------------------
+
+cleanup() {
+    info "Cleaning up build directory..."
+    rm -rf "${CLONE_DIR}"
+}
+
+# --- Step 6: Success message ----------------------------------------------
+
+print_success() {
+    echo ""
+    info "ZeroClaw installed successfully!"
+    echo ""
+    echo "  To use zeroclaw in your current shell, run:"
+    echo ""
+    echo "    source \"\${HOME}/.cargo/env\""
+    echo ""
+    echo "  To make it permanent, add the line above to your shell profile"
+    echo "  (~/.bashrc, ~/.zshrc, etc.)."
+    echo ""
+    echo "  Then get started:"
+    echo ""
+    echo "    zeroclaw onboard"
+    echo ""
+}
+
+# --- Main -----------------------------------------------------------------
+
+main() {
+    echo ""
+    info "ZeroClaw — Source Install"
+    echo ""
+
+    install_system_deps
+    echo ""
+    install_rust
+    echo ""
+    clone_repo
+    echo ""
+    build_and_install
+    echo ""
+    cleanup
+    echo ""
+    print_success
+}
+
+main