…r & ignore noise

Combines two community contributions and one local correction:

* PR EKKOLearnAI#289 (Sanjays2402): probe /api/sessions on the dashboard URL
  (default :9119) instead of the agent URL (:8642). The agent does not
  serve /api/sessions, which produced a 404 every 15s. Adds a small
  cache so success/failure responses don't refetch every poll. Closes EKKOLearnAI#276.

* PR EKKOLearnAI#288 (Interstellar-code): send Authorization: Bearer
  $HERMES_API_TOKEN on the connection-status probes so a gateway
  secured with API_SERVER_KEY is detected correctly. Adds watch.ignored
  for .runtime/.tanstack/.omc/.omx/coverage/dist/etc. so these noisy
  internal paths don't fire spurious dev reloads.

* Local correction: did NOT add '**/routeTree.gen.ts' to watch.ignored.
  An existing regression test (src/router-route-resolution.test.ts)
  forbids that — ignoring the generated route tree breaks route HMR.
  The real cause of routeTree.gen.ts thrash is multiple concurrent
  vite dev servers writing to the same file (fixed earlier today).

Co-authored-by: Sanjays2402 <Sanjays2402@users.noreply.github.com>
Co-authored-by: Interstellar-code <Interstellar-code@users.noreply.github.com>

…LearnAI#285)

The vite dev server intercepted /api/connection-status with a slim
inline shortcut handler that returned only {ok, mode, backend} \u2014
silently overriding the real route at src/routes/api/connection-status.ts
which returns the full ConnectionStatus payload.

Downstream feature gates (useFeatureCapability, useFeatureAvailable)
read .capabilities from the response. With the slim body, every
capability evaluated to undefined, so dev users got UI states that
looked like 'feature not available' even when the gateway was healthy
and exposing the API.

Fix: drop the inline shortcut entirely. The real route file already
caches via ensureGatewayProbed() (PROBE_TTL_MS), so the cost in dev
is negligible and the payload is correct everywhere.

Closes EKKOLearnAI#285. Also drops the now-unused dashboard URL / token / cache
locals in vite.config.ts that were only used by the deleted handler;
the per-PR work that introduced them (EKKOLearnAI#288, EKKOLearnAI#289) was the
right diagnosis but the wrong fix \u2014 the real route was already
doing it correctly.