Fix static wallpaper rendering and scheduling regressions

[Anthonyy232]

Summary

This fixes the post-v4.0.2 regressions reported in the static wallpaper renderer and makes the wallpaper changer independently pausable without losing album selections.

Root causes

• Scheduled work could read the foreground app's landscape configuration and rotate the target canvas even though the physical display remained portrait.
• Static scaling modes reused the launcher's requested wide wallpaper surface, distorting FIT, STRETCH, and NONE and forcing FILL to scroll.
• Album selection implicitly enabled scheduling, so users could not pause changes while keeping their configuration.

Changes

• Resolve a stable natural display size from the built-in display mode.
• Render all static modes against one physical display panel.
• Center FILL by default and add an explicit persisted horizontal-scrolling opt-in.
• When scrolling is enabled for both targets, write home and lock separately so the lock screen stays centered.
• Add a persistent Wallpaper changing switch; manual changes remain available while paused.
• Remove the unused network loader and transitive ACCESS_NETWORK_STATE permission.
• Update Hilt/coroutines-test and add regression coverage.

Verification

• 271 unit tests passed.
• Android lint passed.
• Android-test APK compiled.
• 9/9 connected tests passed on Android 17; 8/9 passed on Android 16 with the Android-17-only case skipped as expected.
• Device audit verified FIT, FILL, STRETCH, and NONE; portrait and landscape app states; centered and scrolling home output; centered lock output; pause/resume persistence and WorkManager cancellation/recreation.
• Live wallpaper audit verified service activation, EGL/shader initialization, large-texture tiling, image reload/crossfade, double-tap reload, screen-off reload, and blur/darken/vignette/grayscale/parallax updates.
• Final merged manifests contain neither INTERNET nor ACCESS_NETWORK_STATE.

Fixes #538
Fixes #577
Fixes #578
Fixes #580
Fixes #581