The White Balance Selector button in the Edit panel only armed the tool,
so in Compare (which doesn't handle on-image tools) it did nothing while
W opened the photo in Detail with the selector armed. The button now runs
tool.wbPicker like W; a second click still disarms it.
New headless test tests_wb_selector.rs clicks the button in Compare and
expects Detail with the selector armed on the photo that was active; it
fails without the fix (the view stays Compare).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>