[BlackMixture]

Opening Compare from a zoomed image now retains the same detail. Same-shape edits can compare against their original, Hold Original mirrors zoom and pan, and Use → Original preserves the focus. Closing Compare keeps the underlying lightbox open and restores keyboard focus; keyboard hold and late-image-load behavior are covered.

Recognized ComfyUI pinned RAM, Windows commit, and GPU-memory failures now retain the original exception and add targeted guidance. History polling recovers the actual exception when the WebSocket event was missed. Generic CPU allocation errors are not labeled as GPU exhaustion. Troubleshooting documents the reported pinned-memory workaround and the managed-launch limitation.

Validation:

• Full Node suite: 1,345 passed, two loopback tests skipped by sandbox. Both skipped tests subsequently passed outside the sandbox (1,347 passing tests across runs).
• Memory diagnostics rerun after classifier tightening: six passed.
• JavaScript syntax checks and git diff whitespace checks passed.
• Shared comparison UI exercised in an isolated native desktop preview: zoom retained at 349%, keyboard Hold Original matched that scale, Escape preserved the lightbox and restored its Compare button focus. Desktop and 390px phone layouts inspected with synthetic fixtures.

Addresses #64. Improves diagnosis for #79; does not claim to fix upstream memory allocation. The rendering/SageAttention fallback from #74 is intentionally excluded pending further review. No inference flags or rendering graphs change in this PR.