diff --git a/.gitignore b/.gitignore
index 474b2e6..8d91bd2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 nvim-macos-arm64
 nvim.appimage
 .DS_Store
+docs/superpowers
+.worktrees
diff --git a/install/lib/common.sh b/install/lib/common.sh
index 7ec00d6..13a5542 100644
--- a/install/lib/common.sh
+++ b/install/lib/common.sh
@@ -75,16 +75,3 @@ install_fzf() {
     mkdir -p "${local_bin_dir}"
     ln -sf "$HOME/.fzf/bin/fzf" "${local_bin_dir}/fzf"
 }
-
-fix_linux_cli_names() {
-    local local_bin_dir="${HOME}/.local/bin"
-    mkdir -p "${local_bin_dir}"
-
-    if ! command -v fd >/dev/null 2>&1 && command -v fdfind >/dev/null 2>&1; then
-        ln -sf "$(command -v fdfind)" "${local_bin_dir}/fd"
-    fi
-
-    if ! command -v bat >/dev/null 2>&1 && command -v batcat >/dev/null 2>&1; then
-        ln -sf "$(command -v batcat)" "${local_bin_dir}/bat"
-    fi
-}
diff --git a/install/nvim-bin.sh b/install/nvim-bin.sh
new file mode 100755
index 0000000..b054bed
--- /dev/null
+++ b/install/nvim-bin.sh
@@ -0,0 +1,183 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+NVIM_CHANNEL="nightly"
+
+LOCAL_DIR="${HOME}/.local"
+LOCAL_BIN_DIR="${LOCAL_DIR}/bin"
+
+OS="$(uname -s)"
+ARCH="$(uname -m)"
+
+mkdir -p "${LOCAL_DIR}" "${LOCAL_BIN_DIR}"
+
+need_cmd() {
+    command -v "$1" >/dev/null 2>&1 || {
+        echo "Error: required command '$1' not found."
+        exit 1
+    }
+}
+
+append_once() {
+    local line="$1"
+    local file="$2"
+    mkdir -p "$(dirname "$file")"
+    touch "$file"
+    grep -Fqx "$line" "$file" || echo "$line" >> "$file"
+}
+
+apt_install() {
+    need_cmd apt-get
+    if [[ "$(id -u)" -eq 0 ]]; then
+        apt-get update
+        apt-get install -y "$@"
+    elif command -v sudo >/dev/null 2>&1; then
+        sudo apt-get update
+        sudo apt-get install -y "$@"
+    else
+        echo "Error: need root or sudo to install packages with apt-get."
+        exit 1
+    fi
+}
+
+brew_install() {
+    need_cmd brew
+    brew install "$@"
+}
+
+ensure_local_bin_path() {
+    local path_line='export PATH="$HOME/.local/bin:$PATH"'
+    append_once "${path_line}" "$HOME/.bashrc"
+    append_once "${path_line}" "$HOME/.zshrc"
+}
+
+install_fzf() {
+    if command -v fzf >/dev/null 2>&1; then
+        return
+    fi
+    echo "Installing fzf..."
+    need_cmd git
+    if [[ ! -d "$HOME/.fzf" ]]; then
+        git clone --depth 1 https://github.com/junegunn/fzf.git "$HOME/.fzf"
+    fi
+    "$HOME/.fzf/install" --bin --no-update-rc
+    mkdir -p "${LOCAL_BIN_DIR}"
+    ln -sf "$HOME/.fzf/bin/fzf" "${LOCAL_BIN_DIR}/fzf"
+}
+
+fix_linux_cli_names() {
+    mkdir -p "${LOCAL_BIN_DIR}"
+    if ! command -v fd >/dev/null 2>&1 && command -v fdfind >/dev/null 2>&1; then
+        ln -sf "$(command -v fdfind)" "${LOCAL_BIN_DIR}/fd"
+    fi
+    if ! command -v bat >/dev/null 2>&1 && command -v batcat >/dev/null 2>&1; then
+        ln -sf "$(command -v batcat)" "${LOCAL_BIN_DIR}/bat"
+    fi
+}
+
+install_linux_deps() {
+    echo "Installing Neovim dependencies for Linux..."
+    apt_install \
+        curl \
+        git \
+        ripgrep \
+        fd-find \
+        bat \
+        clang \
+        libclang-dev
+
+    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+    . "$HOME/.cargo/env"
+    cargo install --locked tree-sitter-cli
+
+    fix_linux_cli_names
+    install_fzf
+}
+
+install_macos_deps() {
+    echo "Installing Neovim dependencies for macOS..."
+    brew_install curl \
+        git \
+        fd \
+        ripgrep \
+        bat \
+        llvm \
+        tree-sitter-cli
+
+    install_fzf
+}
+
+install_nvim_macos() {
+    need_cmd curl
+    need_cmd tar
+
+    local name file url
+
+    case "${ARCH}" in
+        arm64)  name="nvim-macos-arm64" ;;
+        x86_64) name="nvim-macos-x86_64" ;;
+        *)
+            echo "Unsupported macOS architecture: ${ARCH}"
+            exit 1
+            ;;
+    esac
+
+    file="${name}.tar.gz"
+    url="https://github.com/neovim/neovim/releases/download/${NVIM_CHANNEL}/${file}"
+
+    echo "Downloading Neovim ${NVIM_CHANNEL} for macOS (${ARCH})..."
+    curl -fL "${url}" -o "/tmp/${file}"
+
+    rm -rf "${LOCAL_DIR:?}/${name}" "${LOCAL_BIN_DIR}/nvim"
+    tar xzf "/tmp/${file}" -C "${LOCAL_DIR}"
+    ln -sf "${LOCAL_DIR}/${name}/bin/nvim" "${LOCAL_BIN_DIR}/nvim"
+
+    rm -f "/tmp/${file}"
+}
+
+install_nvim_linux() {
+    need_cmd curl
+
+    local name url
+
+    case "${ARCH}" in
+        x86_64)         name="nvim-linux-x86_64.appimage" ;;
+        aarch64|arm64)  name="nvim-linux-arm64.appimage" ;;
+        *)
+            echo "Unsupported Linux architecture: ${ARCH}"
+            exit 1
+            ;;
+    esac
+
+    url="https://github.com/neovim/neovim/releases/download/${NVIM_CHANNEL}/${name}"
+
+    echo "Downloading Neovim ${NVIM_CHANNEL} AppImage for Linux (${ARCH})..."
+    curl -fL "${url}" -o "${LOCAL_BIN_DIR}/nvim"
+    chmod u+x "${LOCAL_BIN_DIR}/nvim"
+}
+
+main() {
+    case "${OS}" in
+        Darwin)
+            install_macos_deps
+            install_nvim_macos
+            ;;
+        Linux)
+            install_linux_deps
+            install_nvim_linux
+            ;;
+        *)
+            echo "Unsupported operating system: ${OS}"
+            exit 1
+            ;;
+    esac
+
+    ensure_local_bin_path
+
+    echo
+    echo "Neovim binary installation completed."
+}
+
+if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
+    main "$@"
+fi
diff --git a/install/nvim.sh b/install/nvim.sh
index 84ab15e..f850d5d 100755
--- a/install/nvim.sh
+++ b/install/nvim.sh
@@ -3,110 +3,13 @@ set -euo pipefail
 
 SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
 REPO_ROOT="$(cd -- "${SCRIPT_DIR}/.." && pwd)"
-# shellcheck source=lib/common.sh
-source "${SCRIPT_DIR}/lib/common.sh"
 
-NVIM_CHANNEL="nightly"
+# shellcheck source=install/nvim-bin.sh
+source "${SCRIPT_DIR}/nvim-bin.sh"
 
-LOCAL_DIR="${HOME}/.local"
-LOCAL_BIN_DIR="${LOCAL_DIR}/bin"
 CONFIG_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/nvim"
 NVIM_SOURCE_DIR="${REPO_ROOT}/nvim"
 
-OS="$(uname -s)"
-ARCH="$(uname -m)"
-
-mkdir -p "${LOCAL_DIR}" "${LOCAL_BIN_DIR}"
-
-install_linux_deps() {
-    echo "Installing Neovim dependencies for Linux..."
-    apt_install \
-        curl \
-        git \
-        ripgrep \
-        fd-find \
-        bat \
-        clang \
-        libclang-dev
-
-    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
-    . "$HOME/.cargo/env"
-    cargo install --locked tree-sitter-cli
-
-    fix_linux_cli_names
-    install_fzf
-}
-
-install_macos_deps() {
-    echo "Installing Neovim dependencies for macOS..."
-    brew_install curl \
-        git \
-        fd \
-        ripgrep \
-        bat \
-        llvm \
-        tree-sitter-cli
-
-    install_fzf
-}
-
-install_nvim_macos() {
-    need_cmd curl
-    need_cmd tar
-
-    local name file url
-
-    case "${ARCH}" in
-        arm64)
-            name="nvim-macos-arm64"
-            ;;
-        x86_64)
-            name="nvim-macos-x86_64"
-            ;;
-        *)
-            echo "Unsupported macOS architecture: ${ARCH}"
-            exit 1
-            ;;
-    esac
-
-    file="${name}.tar.gz"
-    url="https://github.com/neovim/neovim/releases/download/${NVIM_CHANNEL}/${file}"
-
-    echo "Downloading Neovim ${NVIM_CHANNEL} for macOS (${ARCH})..."
-    curl -fL "${url}" -o "/tmp/${file}"
-
-    rm -rf "${LOCAL_DIR:?}/${name}" "${LOCAL_BIN_DIR}/nvim"
-    tar xzf "/tmp/${file}" -C "${LOCAL_DIR}"
-    ln -sf "${LOCAL_DIR}/${name}/bin/nvim" "${LOCAL_BIN_DIR}/nvim"
-
-    rm -f "/tmp/${file}"
-}
-
-install_nvim_linux() {
-    need_cmd curl
-
-    local name url
-
-    case "${ARCH}" in
-        x86_64)
-            name="nvim-linux-x86_64.appimage"
-            ;;
-        aarch64|arm64)
-            name="nvim-linux-arm64.appimage"
-            ;;
-        *)
-            echo "Unsupported Linux architecture: ${ARCH}"
-            exit 1
-            ;;
-    esac
-
-    url="https://github.com/neovim/neovim/releases/download/${NVIM_CHANNEL}/${name}"
-
-    echo "Downloading Neovim ${NVIM_CHANNEL} AppImage for Linux (${ARCH})..."
-    curl -fL "${url}" -o "${LOCAL_BIN_DIR}/nvim"
-    chmod u+x "${LOCAL_BIN_DIR}/nvim"
-}
-
 install_nvim_config() {
     [[ -d "${NVIM_SOURCE_DIR}" ]] || {
         echo "Error: Neovim config directory not found: ${NVIM_SOURCE_DIR}"
@@ -119,7 +22,7 @@ install_nvim_config() {
     cp -R "${NVIM_SOURCE_DIR}" "${CONFIG_DIR}"
 }
 
-main() {
+main_local() {
     case "${OS}" in
         Darwin)
             install_macos_deps
@@ -146,4 +49,4 @@ main() {
     echo "  nvim --version"
 }
 
-main "$@"
+main_local "$@"
diff --git a/install/zk-bin.sh b/install/zk-bin.sh
new file mode 100755
index 0000000..c41d992
--- /dev/null
+++ b/install/zk-bin.sh
@@ -0,0 +1,130 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+OS="$(uname -s)"
+ARCH="$(uname -m)"
+
+ZK_VERSION="v0.15.2"
+
+ZK_INSTALL_DIR="$HOME/.local/bin"
+ZK_BIN="${ZK_INSTALL_DIR}/zk"
+
+TMPDIR_TO_CLEANUP=""
+cleanup_tmpdir() {
+    [[ -n "${TMPDIR_TO_CLEANUP:-}" ]] && rm -rf -- "${TMPDIR_TO_CLEANUP}"
+}
+
+need_cmd() {
+    command -v "$1" >/dev/null 2>&1 || {
+        echo "Error: required command '$1' not found."
+        exit 1
+    }
+}
+
+apt_install() {
+    need_cmd apt-get
+    if [[ "$(id -u)" -eq 0 ]]; then
+        apt-get update
+        apt-get install -y "$@"
+    elif command -v sudo >/dev/null 2>&1; then
+        sudo apt-get update
+        sudo apt-get install -y "$@"
+    else
+        echo "Error: need root or sudo to install packages with apt-get."
+        exit 1
+    fi
+}
+
+brew_install() {
+    need_cmd brew
+    brew install "$@"
+}
+
+install_linux_deps() {
+    echo "Installing zk dependencies for Ubuntu..."
+    apt_install curl tar
+}
+
+install_macos_deps() {
+    echo "Installing zk dependencies for macOS..."
+    brew_install curl gnu-tar
+}
+
+get_zk_platform() {
+    case "${OS}" in
+        Linux)  echo "linux" ;;
+        Darwin) echo "macos" ;;
+        *)
+            echo "Unsupported operating system: ${OS}" >&2
+            exit 1
+            ;;
+    esac
+}
+
+get_zk_arch() {
+    case "${ARCH}" in
+        x86_64|amd64)  echo "amd64" ;;
+        arm64|aarch64) echo "arm64" ;;
+        i386|i686)     echo "i386" ;;
+        *)
+            echo "Unsupported architecture: ${ARCH}" >&2
+            exit 1
+            ;;
+    esac
+}
+
+install_zk_from_release() {
+    echo "Installing zk ${ZK_VERSION} from prebuilt release..."
+
+    need_cmd curl
+    need_cmd tar
+    need_cmd install
+    need_cmd mktemp
+
+    local platform arch asset_name download_url extracted_bin
+    platform="$(get_zk_platform)"
+    arch="$(get_zk_arch)"
+
+    asset_name="zk-${ZK_VERSION}-${platform}-${arch}.tar.gz"
+    download_url="https://github.com/zk-org/zk/releases/download/${ZK_VERSION}/${asset_name}"
+
+    TMPDIR_TO_CLEANUP="$(mktemp -d)"
+    trap cleanup_tmpdir EXIT
+
+    mkdir -p "${ZK_INSTALL_DIR}"
+
+    echo "Downloading ${asset_name}..."
+    curl -fL "${download_url}" -o "${TMPDIR_TO_CLEANUP}/${asset_name}"
+
+    echo "Extracting ${asset_name}..."
+    tar -xzf "${TMPDIR_TO_CLEANUP}/${asset_name}" -C "${TMPDIR_TO_CLEANUP}"
+
+    extracted_bin="$(find "${TMPDIR_TO_CLEANUP}" -type f -name zk | head -n 1 || true)"
+    if [[ -z "${extracted_bin}" ]]; then
+        echo "Error: could not find zk binary after extracting ${asset_name}"
+        exit 1
+    fi
+
+    install -m 0755 "${extracted_bin}" "${ZK_BIN}"
+}
+
+main() {
+    case "${OS}" in
+        Darwin) install_macos_deps ;;
+        Linux)  install_linux_deps ;;
+        *)
+            echo "Unsupported operating system: ${OS}"
+            exit 1
+            ;;
+    esac
+
+    install_zk_from_release
+
+    echo
+    echo "zk binary installation completed."
+    "${ZK_BIN}" --version
+}
+
+if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
+    main "$@"
+fi
diff --git a/install/zk.sh b/install/zk.sh
index 8e3da19..1458899 100755
--- a/install/zk.sh
+++ b/install/zk.sh
@@ -3,16 +3,9 @@ set -euo pipefail
 
 SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
 REPO_ROOT="$(cd -- "${SCRIPT_DIR}/.." && pwd)"
-# shellcheck source=lib/common.sh
-source "${SCRIPT_DIR}/lib/common.sh"
 
-OS="$(uname -s)"
-ARCH="$(uname -m)"
-
-ZK_VERSION="v0.15.2"
-
-ZK_INSTALL_DIR="$HOME/.local/bin"
-ZK_BIN="${ZK_INSTALL_DIR}/zk"
+# shellcheck source=install/zk-bin.sh
+source "${SCRIPT_DIR}/zk-bin.sh"
 
 ZK_SOURCE_DIR="${REPO_ROOT}/zk"
 ZK_SOURCE_CONFIG="${ZK_SOURCE_DIR}/config.toml"
@@ -23,18 +16,26 @@ ZK_NOTEBOOK_META_DIR="${ZK_NOTEBOOK_DIR}/.zk"
 ZK_NOTEBOOK_CONFIG="${ZK_NOTEBOOK_META_DIR}/config.toml"
 ZK_NOTEBOOK_TEMPLATES_DIR="${ZK_NOTEBOOK_META_DIR}/templates"
 
-cleanup_tmpdir() {
-    [[ -n "${TMPDIR_TO_CLEANUP:-}" ]] && rm -rf -- "${TMPDIR_TO_CLEANUP}"
+append_once() {
+    local line="$1"
+    local file="$2"
+    mkdir -p "$(dirname "$file")"
+    touch "$file"
+    grep -Fqx "$line" "$file" || echo "$line" >> "$file"
 }
 
-install_linux_deps() {
-    echo "Installing zk dependencies for Ubuntu..."
-    apt_install curl tar
-}
+copy_file() {
+    local src="$1"
+    local dst="$2"
 
-install_macos_deps() {
-    echo "Installing zk dependencies for macOS..."
-    brew_install curl gnu-tar
+    [[ -f "${src}" ]] || {
+        echo "Error: source file not found: ${src}"
+        exit 1
+    }
+
+    echo "Copying $(basename "$src")..."
+    mkdir -p "$(dirname "$dst")"
+    cp -f "${src}" "${dst}"
 }
 
 setup_shell_init() {
@@ -47,68 +48,6 @@ setup_shell_init() {
     append_once 'export ZK_NOTEBOOK_DIR="$HOME/notebook"' "$HOME/.bashrc"
 }
 
-get_zk_platform() {
-    case "${OS}" in
-        Linux) echo "linux" ;;
-        Darwin) echo "macos" ;;
-        *)
-            echo "Unsupported operating system: ${OS}" >&2
-            exit 1
-            ;;
-    esac
-}
-
-get_zk_arch() {
-    case "${ARCH}" in
-        x86_64|amd64) echo "amd64" ;;
-        arm64|aarch64)
-            if [[ "${OS}" == "Darwin" ]]; then
-                echo "arm64"
-            else
-                echo "arm64"
-            fi
-            ;;
-        i386|i686) echo "i386" ;;
-        *)
-            echo "Unsupported architecture: ${ARCH}" >&2
-            exit 1
-            ;;
-    esac
-}
-
-install_zk_from_release() {
-    echo "Installing zk ${ZK_VERSION} from prebuilt release..."
-
-    need_cmd curl
-    need_cmd tar
-    need_cmd install
-    need_cmd mktemp
-
-    local platform arch asset_name download_url extracted_bin
-    platform="$(get_zk_platform)"
-    arch="$(get_zk_arch)"
-
-    asset_name="zk-${ZK_VERSION}-${platform}-${arch}.tar.gz"
-    download_url="https://github.com/zk-org/zk/releases/download/${ZK_VERSION}/${asset_name}"
-
-    TMPDIR_TO_CLEANUP="$(mktemp -d)"
-    trap cleanup_tmpdir EXIT
-
-    echo "Downloading ${asset_name}..."
-    curl -fL "${download_url}" -o "${TMPDIR_TO_CLEANUP}/${asset_name}"
-
-    echo "Extracting ${asset_name}..."
-    tar -xzf "${TMPDIR_TO_CLEANUP}/${asset_name}" -C "${TMPDIR_TO_CLEANUP}"
-
-    extracted_bin="$(find "${TMPDIR_TO_CLEANUP}" -type f -name zk | head -n 1 || true)"
-    if [[ -z "${extracted_bin}" ]]; then
-        echo "Error: could not find zk binary after extracting ${asset_name}"
-        exit 1
-    fi
-
-    install -m 0755 "${extracted_bin}" "${ZK_BIN}"
-}
-
 bootstrap_zk_notebook() {
     [[ -f "${ZK_SOURCE_CONFIG}" ]] || {
         echo "Error: zk config file not found: ${ZK_SOURCE_CONFIG}"
@@ -151,14 +90,10 @@ bootstrap_zk_notebook() {
     mkdir -p "${ZK_NOTEBOOK_DIR}/daily"
 }
 
-main() {
+main_local() {
     case "${OS}" in
-        Darwin)
-            install_macos_deps
-            ;;
-        Linux)
-            install_linux_deps
-            ;;
+        Darwin) install_macos_deps ;;
+        Linux)  install_linux_deps ;;
         *)
             echo "Unsupported operating system: ${OS}"
             exit 1
@@ -174,4 +109,4 @@ main() {
     "${ZK_BIN}" --version
 }
 
-main "$@"
+main_local "$@"