feat: distribute bark via npm and Homebrew

[Abhinav-Chdhary]

Summary

Adds two compiler-free, one-line install paths for bark, so users don't need a Go toolchain or a C compiler:

brew install debkanchan/tap/bark      # macOS / Linux
npm install -g @debkanchan/bark       # any platform with Node.js

Today the only install paths are go install (which silently requires a C compiler, because the tree-sitter bindings need CGO) and manual binary downloads. This PR layers npm + Homebrew distribution on top of the existing release binaries — no changes to the Go source or the build matrix.

What's included

npm (@debkanchan/bark)

Uses the platform-packages + optionalDependencies pattern (same as esbuild / biome / swc):

• A tiny Node launcher (npm/bark/bin/bark) that resolves and spawnSyncs the correct binary — no shell, args passed as an array.
• Five per-platform packages @debkanchan/bark-<os>-<arch> (linux x64/arm64, darwin x64/arm64, win32 x64), each gated by npm's os/cpu fields so only the matching one installs.
• npm/build.mjs stamps versions and stages the release binaries into each package at publish time.

Homebrew (debkanchan/tap/bark)

• scripts/gen-homebrew-formula.mjs generates Formula/bark.rb from the release archives + their .sha256 sidecars (validates the checksum format) and the release job commits it to a tap repo.

Release automation (.github/workflows/release.yml)

• Two new jobs gated on the existing release job: npm (publishes the 5 platform packages, then the main package) and homebrew (generates the formula and pushes it to the tap).
• Both no-op cleanly (green-skip) until their secrets are configured, so they never break a release before setup.

Docs

• README install section now leads with brew/npm; go install is kept but documented as requiring a C compiler (CGO).

Verified locally (before opening this PR)

• Homebrew: generated the formula against the real v0.1.1 release artifacts and ran the actual brew install via a local tap → download + checksum verification + install + brew test pass + brew audit clean.
• npm: published all 6 packages to a local registry (verdaccio) and installed both npm install and npm install -g → only the host-matching platform package installs (os/cpu gating works), launcher runs, exit codes and --format json pass through.

Two bugs were caught and fixed during that testing:

1. The Homebrew formula's test captured only stdout, but bark --help writes usage to stderr (→ --help 2>&1); and def install inside the platform blocks violated Homebrew's RuboCop (→ single top-level install using Dir["bark-*"]).
2. npm publish npm/<pkg> is interpreted by npm as a GitHub user/repo shorthand rather than a folder (→ ./npm/<pkg>).

Maintainer setup required before a tagged release will publish

• npm: an NPM_TOKEN repo secret with publish access to the @debkanchan scope (and confirm the scope/name).
• Homebrew: a debkanchan/homebrew-tap repo + a HOMEBREW_TAP_TOKEN secret (PAT with write access to it).

Until those exist, the new jobs skip silently and releases behave exactly as before.

🤖 Generated with Claude Code