Clicking "Summarize" now runs the summary in the background (when a Processor is
wired) instead of only queuing it. The handler flips the DB flag, kicks off the
work on a detached context, and returns an animated "processing" card that polls
GET /v/{id}/status every 2s via HTMX. Status returns the summary card once it
lands (no poll → polling stops), the animation while in-flight, or the Queued
card otherwise. Queue-only behaviour is unchanged when no Processor is set.
The spinner is a CSS-only cross-fade of three ASCII tapir frames — no JS, honours
prefers-reduced-motion.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
