Summary

Brew users currently get a different (and broken-looking) command than npm users. This PR switches the formula to install via the npm tarball so both paths produce the same install.

Background

The release on `LambdaTest/kane-cli` ships these binaries:
```
kane-cli-darwin-arm64 ← actually v16-runner, renamed
kane-cli-linux-x64 ← same
kane-cli-win-x64.exe ← same
```

Those are the bare Python/Nuitka agent (`v16-runner`). The actual user-facing CLI is the Node.js TUI shipped via `@testmuai/kane-cli` on npm — that wraps `v16-runner` as a subprocess.

The old formula installed the bare runner as `kane-cli`, so:

• `brew install LambdaTest/kane/kane-cli && kane-cli` → no TUI, expects NDJSON config on stdin, errors out
• `npm install -g @testmuai/kane-cli && kane-cli` → interactive Ink TUI

Approach

Adopt the agent-browser pattern — Homebrew's existing formula for a similar Node-based CLI tool.

```ruby
url "https://registry.npmjs.org/@testmuai/kane-cli/-/kane-cli-0.2.0.tgz"
sha256 "..."
depends_on "node"

def install
system "npm", "install", std_npm_args
bin.install_symlink libexec.glob("bin/")
end
```

`npm install` resolves `@testmuai/kane-cli`'s `optionalDependencies` and pulls only the matching platform binary package — same as the npm install path.

Auto-update workflow

Rewritten so it works against the new formula structure:

• Polls npmjs.com for the new version (up to 2min — handles npm CDN propagation)
• Computes tarball sha256 directly from the registry
• Updates `url` / `sha256` / `version` (single occurrences each — no per-platform blocks anymore)
• Idempotent — skips commit if nothing changed

Test plan

• `brew install LambdaTest/kane/kane-cli` after this merges and the repo is public — should run `npm install`, install Node-based TUI
• `kane-cli --version` prints `0.2.0`
• `kane-cli` (no args) launches the same Ink TUI as the npm install
• On next `build-cli.yml` public release, the formula auto-update workflow polls for the new version and updates the formula in one step

🤖 Generated with Claude Code