feat: add Platform::map_shared and wire memory delegation to page mapping

crates/kernel/src/syscall/capability.rs

@@ -39,10 +39,22 @@ impl<P: Platform> Kernel<P> {
             Err(e) => return SyscallOutcome::Complete(SyscallResult::Error(e)),
         };
 
-        match self.grant_cap(target_pid, resource, restricted) {
-            Ok(_) => SyscallOutcome::Complete(SyscallResult::Ok),
-            Err(e) => SyscallOutcome::Complete(SyscallResult::Error(e)),
+        if let Err(e) = self.grant_cap(target_pid, resource.clone(), restricted) {
+            return SyscallOutcome::Complete(SyscallResult::Error(e));
         }
+
+        if let domain::resource::Resource::Memory(region_id) = &resource {
+            if let Some(region) = self.regions.get(*region_id) {
+                self.platform.map_shared(
+                    target_pid,
+                    region.base(),
+                    region.size(),
+                    restricted,
+                );
+            }
+        }
+
+        SyscallOutcome::Complete(SyscallResult::Ok)
     }
 
     pub(crate) fn handle_revoke(