Initial dotfiles: portable shell configs, Brewfile, and setup guide

Cleaned up for new machine portability: removed hardcoded paths,
EOL packages, and redundant version managers. Consolidated NVM
loading, added work git identity support via includeIf.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

install.sh

@@ -0,0 +1,64 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+DOTFILES_DIR="$(cd "$(dirname "$0")" && pwd)"
+
+# Colors for output
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+RED='\033[0;31m'
+NC='\033[0m'
+
+info()  { echo -e "${GREEN}[OK]${NC} $1"; }
+warn()  { echo -e "${YELLOW}[SKIP]${NC} $1"; }
+err()   { echo -e "${RED}[ERROR]${NC} $1"; }
+
+link_file() {
+    local src="$DOTFILES_DIR/$1"
+    local dest="$HOME/$2"
+    local dest_dir
+    dest_dir="$(dirname "$dest")"
+
+    # Create parent directory if needed
+    [[ -d "$dest_dir" ]] || mkdir -p "$dest_dir"
+
+    if [[ -L "$dest" ]]; then
+        # Already a symlink — update it
+        rm "$dest"
+        ln -s "$src" "$dest"
+        info "Updated symlink: $dest -> $src"
+    elif [[ -e "$dest" ]]; then
+        # Real file exists — back it up
+        mv "$dest" "${dest}.backup.$(date +%s)"
+        ln -s "$src" "$dest"
+        warn "Backed up existing $dest and created symlink"
+    else
+        ln -s "$src" "$dest"
+        info "Created symlink: $dest -> $src"
+    fi
+}
+
+echo ""
+echo "=== Dotfiles Installer ==="
+echo "This will symlink dotfiles from $DOTFILES_DIR into your home directory."
+echo "Existing files will be backed up with a .backup.* suffix."
+echo ""
+
+# Symlink dotfiles
+link_file "zshrc"             ".zshrc"
+link_file "zshenv"            ".zshenv"
+link_file "p10k.zsh"          ".p10k.zsh"
+link_file "bashrc"            ".bashrc"
+link_file "bash_profile"      ".bash_profile"
+link_file "profile"           ".profile"
+link_file "gitconfig"         ".gitconfig"
+link_file "gitignore_global"  ".gitignore_global"
+link_file "fzf.zsh"           ".fzf.zsh"
+
+echo ""
+echo "=== Symlinks complete ==="
+echo ""
+echo "Next steps:"
+echo "  1. Run: source ~/.zshrc"
+echo "  2. Run: p10k configure   (if you want to re-run the Powerlevel10k wizard)"
+echo ""