v4.12.0 — Settings, solved; the desktop's icon theme in the panel

What changed

Every setting is one row now. The settings panel drew rows three different ways — only some were search targets, a row whose prerequisite was unmet disappeared instead of explaining itself, and the search index had drifted from what was on screen. One row contract now owns the behaviour: all 88 indexed settings are reachable from the search box, a dependent row stays readable with an explanation and a Go to prerequisite button, and searching never enables anything. The pages are named around what you do there: Look, Position & visibility, Apps & windows, Organize dock.

The desktop's icon theme is in the panel. Look → Icon theme reads the theme the whole desktop uses, lists every icon theme installed on the machine, searches them, and applies one with a click — gsettings, both GTK settings files, ~/.icons/default, Omarchy's staged theme, and the KDE/Qt files when they exist, so every app changes at once. Install WhiteSur fetches the macOS Big Sur icon set once into ~/.local/share/icons and applies it; after that it is just another chip in the list.

Theme-first icons, from the first scan. The dock's icon index now walks the active theme's inheritance chain immediately. Before, the scan that starts at load, before the desktop answers which theme it uses, could leave fallback artwork in the index for the rest of the session.

Docs. The settings gallery in the README is recaptured from the real panel and now shows the six pages that exist.

Verification

• 273 Node + 126 Python unit tests, node --check ×18, qmllint 0 errors, structure/security/i18n/manifest/plugin gates clean.
• The live settings suite drives all 88 search targets, the icon-theme search and the WhiteSur row through the real QML with synthetic Qt keys, and leaves the desktop's config, shell PID and monitors unchanged.
• tests/smoke-test.sh passes against the running shell; the WhiteSur install path was exercised end to end in a throwaway home directory with the pinned upstream release.

Honest limits: the WhiteSur button needs network and git; the README screenshots come from a probe instance over a copy of the owner's config, not from the live desktop.