Add panel-wide styles and the Morph hub (#26)

Panel appearance now applies to the whole panel, with seven styles: Floating, Capsules, Notch, Edge to edge, Fused islands, Adaptive and Morph.

- Share composition, geometry, and motion through the renderer-independent `ferese-panel` crate, including native materials, input regions, and Settings previews.
- Add the Morph hub with media, calendar, notifications, controls, workspace previews, hover feedback, and attached mode. Keep recording and low-battery status visible and respect window clearance.
- Cache workspace preview geometry, draw thumbnails directly, centralize Morph transitions, and keep rendering settings local to each shell instance.
- Put Record Screen in the Morph header and show the display control only when an external monitor is connected. Update panel documentation, the desktop screenshot, and native check style names.

Local validation included 660 compositor tests, 191 shell tests, isolated preview-cache checks, GPU Morph captures at 1×/1.25×/1.5×, formatting, and Clippy with warnings denied. The final header change passed all 23 Morph tests. Release workflow jobs are skipped for this PR.

protocols/ferese-effects-v1.xml

@@ -22,7 +22,7 @@
     DEALINGS IN THE SOFTWARE.
   </copyright>
 
-  <interface name="ferese_effects_manager_v1" version="5">
+  <interface name="ferese_effects_manager_v1" version="6">
     <description summary="assign semantic material roles to surfaces">
       This private global is visible only to clients granted the Ferese effects
       capability. Roles describe compositor-owned appearance policy and do not
@@ -48,7 +48,7 @@
     </enum>
   </interface>
 
-  <interface name="ferese_surface_effects_v1" version="5">
+  <interface name="ferese_surface_effects_v1" version="6">
     <description summary="semantic material role for one surface">
       The role affects only compositor rendering. It does not change surface
       geometry, input, focus, stacking, or the surface's Wayland role.
@@ -121,5 +121,24 @@
       <arg name="opacity" type="uint"/>
       <arg name="region_opacities" type="array"/>
     </request>
+    <request name="set_panel_presentation" since="6">
+      <description summary="commit a bounded panel shape with its content">
+        Panel-only material presentation. Regions are bounded capture/damage
+        rectangles in the set_regions format. Shapes are native-endian binary32
+        tuples (x,y,width,height,top-left,top-right,bottom-right,bottom-left,
+        operation,blend-zone). Operations: 0 rounded union, 1 rounded cutout,
+        2..5 rectangular concave patches whose circle centers are bottom-left,
+        bottom-right, top-right, top-left. Blend zones 1..3 fuse independently;
+        zone 0 never fuses. At most 32 primitives and one cutout are accepted.
+        All coordinates must be finite and bounded by 32768 logical pixels.
+        Invalid requests leave pending state unchanged. Empty shapes require
+        empty regions. Input remains controlled by wl_surface.set_input_region.
+        This presentation becomes visible atomically with the next surface commit.
+      </description>
+      <arg name="regions" type="array"/>
+      <arg name="shapes" type="array"/>
+      <arg name="fusion" type="fixed" summary="polynomial smooth-min strength, 0..256 logical pixels"/>
+      <arg name="opacity" type="uint"/>
+    </request>
   </interface>
 </protocol>