Add npm package for bd with native binaries (bd-febc)

Implements @beads/bd npm package for easy installation in Node.js
environments, especially Claude Code for Web.

Features:
- Automatic platform-specific binary download during postinstall
- CLI wrapper that invokes native bd binary
- Full feature parity with standalone bd
- Works with SessionStart hooks for auto-installation

Package structure:
- bin/bd.js: Node.js CLI wrapper
- scripts/postinstall.js: Downloads correct binary from GitHub releases
- scripts/test.js: Verification tests
- Comprehensive documentation (6 guides)

Published to npm: https://www.npmjs.com/package/@beads/bd

Benefits vs WASM:
- Full SQLite support (no custom VFS)
- Better performance (native vs WASM)
- Simpler implementation and maintenance
- All commands work identically

Closes bd-febc, bd-be7a, bd-e2e6, bd-f282, bd-87a0, bd-b54c

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

npm-package/README.md

@@ -0,0 +1,124 @@
+# @beads/bd - Beads Issue Tracker
+
+[![npm version](https://img.shields.io/npm/v/@beads/bd)](https://www.npmjs.com/package/@beads/bd)
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
+
+**Give your coding agent a memory upgrade**
+
+Beads is a lightweight memory system for coding agents, using a graph-based issue tracker. This npm package provides easy installation of the native bd binary for Node.js environments, including Claude Code for Web.
+
+## Installation
+
+```bash
+npm install -g @beads/bd
+```
+
+Or as a project dependency:
+
+```bash
+npm install --save-dev @beads/bd
+```
+
+## What is Beads?
+
+Beads is an issue tracker designed specifically for AI coding agents. It provides:
+
+- ✨ **Zero setup** - `bd init` creates project-local database
+- 🔗 **Dependency tracking** - Four dependency types (blocks, related, parent-child, discovered-from)
+- 📋 **Ready work detection** - Automatically finds issues with no open blockers
+- 🤖 **Agent-friendly** - `--json` flags for programmatic integration
+- 📦 **Git-versioned** - JSONL records stored in git, synced across machines
+- 🌍 **Distributed by design** - Share one logical database via git
+
+## Quick Start
+
+After installation, initialize beads in your project:
+
+```bash
+bd init
+```
+
+Then tell your AI agent to use bd for task tracking instead of markdown:
+
+```bash
+echo "Use 'bd' commands for issue tracking instead of markdown TODOs" >> AGENTS.md
+```
+
+Your agent will automatically:
+- Create and track issues during work
+- Manage dependencies between tasks
+- Find ready work with `bd ready`
+- Keep long-term context across sessions
+
+## Common Commands
+
+```bash
+# Find ready work
+bd ready --json
+
+# Create an issue
+bd create "Fix bug" -t bug -p 1
+
+# Show issue details
+bd show bd-a1b2
+
+# List all issues
+bd list --json
+
+# Update status
+bd update bd-a1b2 --status in_progress
+
+# Add dependency
+bd dep add bd-f14c bd-a1b2
+
+# Close issue
+bd close bd-a1b2 --reason "Fixed"
+```
+
+## Claude Code for Web Integration
+
+To auto-install bd in Claude Code for Web sessions, add to your SessionStart hook:
+
+```bash
+# .claude/hooks/session-start.sh
+npm install -g @beads/bd
+bd init --quiet
+```
+
+This ensures bd is available in every new session without manual setup.
+
+## Platform Support
+
+This package downloads the appropriate native binary for your platform:
+
+- **macOS**: darwin-amd64, darwin-arm64
+- **Linux**: linux-amd64, linux-arm64
+- **Windows**: windows-amd64
+
+## Full Documentation
+
+For complete documentation, see the [beads GitHub repository](https://github.com/steveyegge/beads):
+
+- [Complete README](https://github.com/steveyegge/beads#readme)
+- [Quick Start Guide](https://github.com/steveyegge/beads/blob/main/QUICKSTART.md)
+- [Installation Guide](https://github.com/steveyegge/beads/blob/main/INSTALLING.md)
+- [FAQ](https://github.com/steveyegge/beads/blob/main/FAQ.md)
+- [Troubleshooting](https://github.com/steveyegge/beads/blob/main/TROUBLESHOOTING.md)
+
+## Why npm Package vs WASM?
+
+This npm package wraps the native bd binary rather than using WebAssembly because:
+
+- ✅ Full SQLite support (no custom VFS needed)
+- ✅ All features work identically to native bd
+- ✅ Better performance (native vs WASM overhead)
+- ✅ Simpler maintenance
+
+## License
+
+MIT - See [LICENSE](LICENSE) for details.
+
+## Support
+
+- [GitHub Issues](https://github.com/steveyegge/beads/issues)
+- [Documentation](https://github.com/steveyegge/beads)