Install Noetica runtime npm dependencies

[mdheller]

Summary

Fixes the Phase 1 local install validation failure where noetica start could not find next after Homebrew install.

Observed on macOS install validation:

> noetica@0.1.0 dev
> next dev --hostname 127.0.0.1 --port 3737

sh: line 1: next: command not found

Root cause: the formula installed the Noetica source payload but did not install runtime npm dependencies into libexec, so npm run dev could not resolve next.

This PR updates Formula/noetica.rb to run:

npm install --omit=dev --ignore-scripts --no-audit --no-fund

inside libexec during install.

Boundary

• Still no brew services path.
• No change to Noetica service supervision model.
• Homebrew remains installer/distribution only.
• Prophet Mesh remains deferred.

Validation target

After merge, rerun on macOS:

brew update
brew reinstall sourceos-linux/tap/noetica
noetica version
noetica doctor --json
noetica smoke --dry-run
noetica start

References the Phase 1 validation log attached to SocioProphet/Noetica#20.