feat(installers): consolidate app installers into host-aware install-apps

Fold macinstaller + install-apt-pkgs + install-tools + install-zellij into a
single host-aware lk-installers/install-apps (macOS->Homebrew, bootstrapping
Homebrew if absent; Linux->apt + upstream installers). Installs the tools the
configs assume (bat, fd, fzf, zoxide, zellij, nvim, btop, htop, tldr) plus the
fzf-git.sh helper and fzf shell integration; idempotent.

link-dotfiles gains --apps to install then link in one shot. .zshrc drops the
redundant brew/system zsh-autosuggestions source (zinit already loads it),
fixing the missing-file error on a fresh box. README documents the new flow.

lk-installers/install-apps

@@ -0,0 +1,99 @@
+#!/usr/bin/env bash
+# Host-aware installer for every CLI tool the dotfiles assume at runtime.
+#
+#   macOS  -> Homebrew (bootstraps Homebrew itself if missing)
+#   Linux  -> apt (Debian/Ubuntu) + upstream installers for tools not in apt
+#
+# zinit and all zsh plugins (powerlevel10k, zsh-autosuggestions,
+# zsh-syntax-highlighting, zsh-completions, zsh-vi-mode, fzf-tab) bootstrap
+# themselves from ~/.zshrc on first shell start — they are NOT installed here.
+#
+# Idempotent: re-running only fills gaps. Pairs with ./link-dotfiles, or run
+# `./link-dotfiles --apps` to install then link in one shot.
+#
+# Consolidates the former macinstaller / install-apt-pkgs / install-tools /
+# install-zellij scripts.
+set -euo pipefail
+
+# fzf-git.sh is a sourced helper (not a package) — same on every platform.
+clone_fzf_git() {
+  if [ -d "$HOME/fzf-git.sh" ]; then
+    echo "fzf-git.sh already cloned — skipping"
+  else
+    git clone --depth 1 https://github.com/junegunn/fzf-git.sh.git "$HOME/fzf-git.sh"
+  fi
+}
+
+install_macos() {
+  if ! command -v brew >/dev/null 2>&1; then
+    echo "Homebrew not found — installing…"
+    /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
+    if   [ -x /opt/homebrew/bin/brew ]; then eval "$(/opt/homebrew/bin/brew shellenv)"
+    elif [ -x /usr/local/bin/brew   ]; then eval "$(/usr/local/bin/brew shellenv)"
+    fi
+  fi
+
+  echo "Installing CLI tools via Homebrew…"
+  brew install \
+    zsh git curl wget stow \
+    bat fd fzf zoxide \
+    zellij neovim btop htop
+  # tldr and neofetch are deprecated/disabled upstream — best-effort so a dead
+  # formula can't abort the run. tlrc is the maintained `tldr` client.
+  brew install tlrc || brew install tldr || echo "tldr unavailable — skipping"
+  brew install neofetch || echo "neofetch unavailable — skipping"
+
+  # fzf key-bindings + completion -> ~/.fzf.zsh (sourced by .zshrc). These flags
+  # make it non-interactive; --no-update-rc stops it editing .zshrc (the repo
+  # owns that file).
+  "$(brew --prefix)/opt/fzf/install" --key-bindings --completion --no-update-rc >/dev/null
+
+  clone_fzf_git
+}
+
+install_linux() {
+  if ! command -v apt >/dev/null 2>&1; then
+    echo "error: Linux app install targets Debian/Ubuntu (apt). Install the tools manually on this distro." >&2
+    exit 1
+  fi
+
+  echo "Installing base packages via apt…"
+  sudo apt update
+  sudo apt install -y --no-install-recommends \
+    neovim vim-nox btop htop neofetch curl wget tldr git zip unzip stow zsh cargo \
+    zsh-autosuggestions zsh-syntax-highlighting
+  sudo apt install -y --no-install-recommends rar unrar || true
+
+  # fzf (vendored under ~/.cache/lk-tools/fzf; .zshrc adds its bin to PATH)
+  if [ ! -d "$HOME/.cache/lk-tools/fzf" ]; then
+    git clone --depth 1 https://github.com/junegunn/fzf.git "$HOME/.cache/lk-tools/fzf"
+    "$HOME/.cache/lk-tools/fzf/install" --key-bindings --completion --no-update-rc
+  fi
+  clone_fzf_git
+
+  # zoxide (upstream installer -> ~/.local/bin, already on PATH)
+  command -v zoxide >/dev/null 2>&1 || \
+    curl -sS https://raw.githubusercontent.com/ajeetdsouza/zoxide/main/install.sh | sh
+
+  # bat + fd: upstream .deb so the binaries are named `bat`/`fd` (Debian ships
+  # them as `batcat`/`fdfind`). amd64 assumed — adjust the URLs on arm64 boxes.
+  if ! command -v bat >/dev/null 2>&1; then
+    wget -qO /tmp/bat.deb https://github.com/sharkdp/bat/releases/download/v0.24.0/bat_0.24.0_amd64.deb
+    sudo apt install -y /tmp/bat.deb
+  fi
+  if ! command -v fd >/dev/null 2>&1; then
+    wget -qO /tmp/fd.deb https://github.com/sharkdp/fd/releases/download/v10.1.0/fd_10.1.0_amd64.deb
+    sudo apt install -y /tmp/fd.deb
+  fi
+
+  # zellij: cargo build, fall back to apt
+  command -v zellij >/dev/null 2>&1 || cargo install zellij || sudo apt install -y zellij
+}
+
+case "$(uname -s)" in
+  Darwin) install_macos ;;
+  Linux)  install_linux ;;
+  *) echo "error: unsupported OS '$(uname -s)'." >&2; exit 1 ;;
+esac
+
+echo "Done. Open a new shell (or 'exec zsh') to pick everything up."