feat(honcho): harden setup flow with bun precheck, self-hosted support, and health probes

Setup skill now checks for bun before any bun invocation and surfaces a
one-line install command when missing. Adds an upfront self-hosted prompt
covering localhost shortcut and custom URL, with optional API key and a
clarifying global-vs-host scope question (default global). The skill now
writes endpoint config directly to ~/.honcho/config.json so the runner
reads it via loadConfig() instead of env-var hand-off.

Adds a reusable health module (src/health.ts) with two probes:
- checkHonchoHealth: unauthenticated GET <root>/health, strips /v3 since
  Honcho's /health lives at host root per upstream docs
- checkHonchoAuth: authenticated SDK queueStatus call, classifies
  failures into no-key / unauthorized / network / unknown

setup-runner runs the health probe before SDK validation as a soft warn
(failed /health doesn't always mean /v3 is unreachable). status-runner
surfaces health and auth as separate lines and short-circuits the rest
of the report on auth failure. New /honcho:health skill wraps both
probes for ad-hoc connectivity debugging.

Also fixes a latent bug: setup-runner's saveConfig call now persists
endpoint, and the host-block defaults are written on every run (idempotent
merge) instead of only on first install, so pre-written self-hosted
configs don't end up missing host defaults.

Author: offendingcommit

plugins/honcho/build.ts

@@ -17,6 +17,7 @@ const entrypoints = [
   "hooks/stop.ts",
   "src/skills/setup-runner.ts",
   "src/skills/status-runner.ts",
+  "src/skills/health-runner.ts",
 ];
 
 const result = await Bun.build({