`serve` (added in #54568) reused cmd_dashboard wholesale, so it still
behaved like a dashboard: it ran a full vite build every launch, mounted
and served the SPA whenever a stray web_dist/ existed, printed
"Hermes Web UI →", and announced HERMES_DASHBOARD_READY. It's the headless
JSON-RPC/WS backend the desktop app and remote clients run — pure socket
clients that never load the browser SPA.
Mark serve with headless_backend=True (resolved once in cmd_dashboard) and:
- skip _build_web_ui entirely on the serve path
- export HERMES_SERVE_HEADLESS=1 so mount_spa() disables the SPA even when a
dist is present — only the JSON-RPC/WS/API surface is reachable
- announce the bind ("Hermes backend listening on host:port") instead of a
browser/auth-gated URL
- print a neutral HERMES_BACKEND_READY sentinel; dashboard keeps the legacy
one and the desktop port-discovery regex matches either
- preserve serve across the named-profile re-exec so it can't rebuild as
dashboard
`hermes dashboard` is unchanged (builds + serves the browser UI). Backward
compatible: old apps only ever spawn dashboard (legacy token + UI intact)
and never invoke serve; the ready-file side channel is name-agnostic. The
one behavior change is that a remote `hermes serve` no longer serves the
browser dashboard as a side effect — that's `hermes dashboard`'s job.
Tests: serve headless_backend contract, SPA-disabled-with-dist, the
HERMES_BACKEND_READY desktop parse (17/17 node), and the existing
serve/dashboard/web_server suites. AGENTS.md documents the behavior.
Clears the ty diff bot's warnings on the new test: pass real callables to
build_dashboard_parser (not object()) and replace the pytest.mark.parametrize
with a plain loop so the file is stdlib-only.
Add a focused contract test for the headless `serve` command (routes to the
shared dashboard handler, headless by default while `dashboard` is not, accepts
the legacy --no-open, shares the same runtime/lifecycle flag surface). Also
refresh the dashboard.py module docstring to cover both commands.
