feat: disabled mode (TENACIOUSLOAD_DISABLED=1) — no-op but keep the loading bar

A one-flag kill-switch: when set, the pack installs no middleware, registers no
refresh routes, computes no fingerprint and exposes no graph node — ComfyUI runs
exactly as if it weren't installed. Only the read-only /tenaciousload/status
route stays so the loading-screen overlay still shows (a generic 'Loading node
definitions…' bar, since there's no build to track). The refresh menu buttons
hide themselves when status reports enabled:false.

Useful for A/B testing or as a safety kill-switch. Requires a restart (the
middleware is installed at startup). Unit-tested both modes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -140,5 +140,14 @@ This pack is a quiet neighbour:
   changes an existing node's inputs *without* adding/removing a node class, use a
   refresh button.
 
+## Disabling (keep only the loading bar)
+Set **`TENACIOUSLOAD_DISABLED=1`** (and restart) to turn the pack into a no-op:
+no caching middleware, no fingerprint, no refresh routes, no graph node — ComfyUI
+behaves exactly as if the pack weren't installed. The **loading-screen status
+bar stays** (it just shows a generic "Loading node definitions…" since there's no
+build to track). Useful for A/B comparing, or as a one-flag kill-switch if you
+ever suspect the cache. Remove the variable (or set it to `0`) and restart to
+re-enable.
+
 ## License
 MIT — see [LICENSE](LICENSE).