Sync upstream master (fd21ecf): server cancel, Z-Image reference crash fix, ggml Vulkan small-BAR placement, one placeholder per image - #35

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@a37ce9120846195fa4ece8f58b268e6043cb2f26, actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020, pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/