Add editable panels and refine shell settings (#18)

* Integrate panel composition, adaptive sizing, and overflow

* Add instance editing controls to panel settings

* Add panel group editing and measured composition preview

* Reorganize panel settings and add drag-and-drop item editing

* Simplify panel settings and place inspectors beside the editor

* Refine Panel & Shell settings, previews, and panel rendering

* Organize settings navigation and modernize packaged panel config

* Support top and bottom panels and refine shell surfaces

Add edge-aware settings, previews, popup placement, notifications, margins, and corner rendering. Preserve translucency in notification and dialog controls, and tighten spacing around the clock and display-mode icon.

* Add workspace styles and fix Settings text rendering

* Make panel allocation independent of measurement order

* Normalize panel item settings and visibility

* Move shell geometry into each panel

* Add independent group surfaces and finalize panel configuration

* Keep panel fit checks and restoration consistent with allocation

* Reject unknown panel item options and namespace metadata

* Reject invalid shell startup configuration and remove old radius fields

* Discover workspace application icons in a background task

* Remove the panel architecture document and improve reference prose

* Let panel media fill available space and improve Settings scrolling

* Preserve panel labels across clipped GPU rendering

* Use matching alpine lake wallpapers for light and dark modes

* Fix panel accessibility and popup lifecycle

Apply Reduce Transparency to panel opacity in the shell, compositor, and
Settings preview. Reject unknown theme tokens before snapshot substitution
and validate the current geometry fields in both consumers.

Dismiss popovers and workspace tooltips after panel layout changes. Handle
bar pointer exits directly and recover workspace hover after reentry without
repeated motion updates. Cover the transitions with regression tests and
update the wallpaper dimensions check for the bundled lake defaults.

* Use tagged Ferese toolkit fixes

* Fix center-only panel spacing and headless text rendering

* Bundle native 4K abstract wallpapers for both appearances

* Dismiss workspace tooltips before captured pointer dispatch

* Verify installed JPEG wallpapers when replacing a release

docs/shortcuts.md

@@ -1,7 +1,7 @@
 # Shortcuts and gestures
 
 `Super` is usually the Windows key. These are the built-in defaults. Open
-**Settings → Shortcuts** to change bindings and gestures or disable the login
+**Settings → Keyboard & mouse → Shortcuts** to change bindings and gestures or disable the login
 guide. Your saved bindings can override these defaults.
 The [example config](../packaging/config.kdl) adds the app, media and arrow-key
 shortcuts listed below.