Release 1.2.0

[Zhen-Bo]

Summary

Fixes completed card previews showing the wrong image in multi-stage workflows,
and adds real-time decoded image updates on the running card as each stage finishes.

Problem

1. Wrong image on completed cards — The /history API returns node outputs
   sorted by node ID (ascending), not by execution order. For multi-stage
   workflows (e.g. base-gen → upscale), the completed card would show the
   base-gen image instead of the final upscaled result.

2. Preview freezes during upscaling — The running card showed live latent
   previews during base-gen sampling, but once the upscale KSampler started,
   the card stayed frozen on the base-gen image and stopped updating.

Solution

• outputCache module — Listens to executed WebSocket events and caches
  the last output per promptId in localStorage (max 200 entries, FIFO eviction).
  firstOutput now performs a cache-first lookup, bypassing the unreliable
  node-ID-sorted dict from the history API.

• onExecuted handler — Updates the running card preview immediately when
  a node completes, so the card transitions through each stage's decoded image
  (base image → upscaled image) as execution progresses.

Commits (4)

1. feat: add outputCache module
2. refactor: integrate outputCache - migrate firstOutput and pass promptId
3. feat: listen to executed events for real-time running card preview
4. test: add preview.js unit tests and fix E2E spec robustness

Testing

• 110 unit tests pass (npm test)
• E2E tests Release 1.1.0 #1–#8 cover all automated checklist items (npm run test:e2e)
• Manual: multi-stage workflow shows latent previews during each KSampler phase
• Manual: running card transitions base image → upscale latents → upscaled image
• Manual: completed card shows the final upscaled image, not the base image
• Manual: completed card image persists across page reload (localStorage cache hit)