add personal snippets and project members

app/policies/personal_snippet_policy.rb

+class PersonalSnippetPolicy < BasePolicy
+  def rules
+    can! :read_personal_snippet if @subject.public?
+    return unless @user
+
+    if @subject.author == @user
+      can! :read_personal_snippet
+      can! :update_personal_snippet
+      can! :admin_personal_snippet
+    end
+
+    if @subject.internal? && !@user.external?
+      can! :read_personal_snippet
+    end
+  end
+end

app/policies/project_member_policy.rb

+class ProjectMemberPolicy < BasePolicy
+  def rules
+    # anonymous users have no abilities here
+    return unless @user
+
+    target_user = @subject.user
+    project = @subject.project
+
+    return if target_user == project.owner
+
+    can_manage = Ability.allowed?(@user, :admin_project_member, project)
+
+    if can_manage
+      can! :update_project_member
+      can! :destroy_project_member
+    end
+
+    if @user == target_user
+      can! :destroy_project_member
+    end
+  end
+end