Reduce idle CPU use and prioritize compositor rendering (#62)

Avoid background title updates when no shell window list is visible, and skip output and capture invalidation for titles outside compositor decorations. Preserve focused titles, fresh window lists and capture privacy.

Request high EGL context priority with fallback, cover rendering and native title behavior in CI, and keep audio recording flowing while video capture is idle.

docs/README.md

@@ -45,7 +45,6 @@ and [guides at that tag](https://github.com/ferese-wm/ferese/tree/v0.1.0-beta/do
 - [Publishing activities](development/activities.md): IPC schema, ownership, limits and templates.
 - [Rust style](development/rust-style.md): module boundaries, ownership, API contracts and enforced checks.
 - [Animation model](animation-model.md): geometry, spring motion, gestures and prediction.
-- [Rendering diagnostics](rendering-performance.md): outcome counters, capture cost and repeatable hardware baselines.
 - [Output management tests](output-management-testing.md): profiles, hotplug and DRM failures.
 - [Client soak testing](native-soak-testing.md).
 - [Website development](../site/README.md).