fix: CON-1445/1446/1447 repair ComfyUI's bundled package drift at boot

[mariiachekmasova-runpod]

ComfyUI pins its bundled packages (comfy-kitchen, frontend, workflow-templates,
embedded-docs) exactly per release. They ship in the image and are never
reinstalled, while the checkout on the network volume can move ahead through
Manager or git. Then main.py aborts importing a comfy_kitchen that predates
it — 8188 never binds while SSH stays up — or the templates package is versions
behind and newly published templates never appear.

start.sh now compares the workspace requirements.txt pins against what is
installed and installs only the ones that disagree, before ComfyUI starts. torch
is excluded; the runtime constraints file already owns it. Deliberately no
--no-deps: the templates meta-package pins its own sub-packages, and skipping
them would update the meta while leaving -core/-json/-media-* stale.

Verified on live pods from the same starting state: the published cuda13.0
dies with AttributeError ... int8_attention_is_available at attention.py:54,
while this branch prints comfy-kitchen: installed 0.2.26, ComfyUI wants 0.2.34,
installs it and serves. Same for the frontend/templates case — the template
browser then lists the MiniMax H3 templates the reports said were missing. With
nothing drifted the check is silent.