Support non-Docker local installations

[thomwolf]

Summary

• add a small installer for the npm-distributed agent CLIs used by non-Docker deployments
• resolve Claude and OpenCode lifecycle helpers from the repository checkout instead of assuming /app/scripts
• declare the native dependency install scripts required by the server and explicitly deny the optional fsevents script
• document the persistent local deployment setup and PATH requirement
• add focused regression coverage for checkout-relative lifecycle helpers

Why

The Docker image installs the agent CLIs and places application scripts under /app, but those build steps and paths do not exist when Agent Manager is launched directly with Node or systemd. As a result, a local backend can report CLIs such as OpenCode as unavailable and install lifecycle hooks that point to files outside the checkout.

This keeps the Docker behavior unchanged while giving local deployments an explicit provisioning path and portable helper locations.

Validation

• npm ci --strict-allow-scripts
• node test/local-install.test.mjs
• node test/opencode-resume.test.mjs (37 checks)
• sh -n scripts/install-local-clis.sh
• git diff --check

The branch was prepared in an isolated worktree and the complete commit was scanned for credentials, tokens, network addresses, Tailscale data, usernames, and absolute host paths before pushing.