Problem

codeboost cannot be installed as designed. The package is private at version 0.0.0 with no published release, so npx codeboost does not work; people run npm start -- --config … or npm run demo from a checkout. The CLI (web/cli.ts) checks only the Node version. A missing git, signed-out gh, stopped Docker or Podman, or missing agent sign-in shows up later as an error from the feature that needs it.

Design (from "How people will install it")

• npx codeboost inside a repo starts the local server and opens the app in the browser.
• At start, codeboost checks for git, a signed-in gh, a running Docker or Podman, and at least one of claude or codex with its sign-in (a claude setup-token token, or Codex's auth.json), and says what is missing.
• Tagging a version publishes to npm and creates a GitHub release.

Scope

package.json (bin, files, publish settings), web/cli.ts (default config from the current repo, opening the browser, the preflight checks), a release workflow in .github/workflows/, README install section. The checks report; they do not change the person's setup. Note that Codex is refused in every phase today (#93), so the agent check must say Claude is needed.

Acceptance

• npm pack output installs and npx starts the server from a clean directory (tested in CI).
• Each missing tool or sign-in gives one named message and a non-zero exit, tested with fakes that answer as the real tools do (version named beside each fake, per CLAUDE.md).
• The release workflow runs on a tag only and publishes nothing from a PR.