Add placeholder content for empty content page (#37114)

- Empty repositories in organization

<img width="877" height="470" alt="image"
src="https://github.com/user-attachments/assets/94dc3992-1ab5-47cc-954a-8c420ec68500"
/>

- Empty projects in organization

<img width="1309" height="358" alt="image"
src="https://github.com/user-attachments/assets/94ef20c5-a6d9-4c39-9457-2a691a98d327"
/>

- Empty code search result in organization and global code search page

<img width="1312" height="345" alt="image"
src="https://github.com/user-attachments/assets/364f2a75-c68f-4302-b3b8-7ba1265622a1"
/>

- Empty worktime in organization

<img width="1301" height="357" alt="image"
src="https://github.com/user-attachments/assets/bb7f2cf8-fb95-463a-94c7-eafa63f56b2b"
/>

templates/org/home.tmpl

@@ -9,8 +9,16 @@
 					<div id="readme_profile" class="render-content markup" data-profile-view-as-member="{{.IsViewingOrgAsMember}}">{{.ProfileReadmeContent}}</div>
 				{{end}}
 				{{template "shared/repo/search" .}}
-				{{template "shared/repo/list" .}}
-				{{template "base/paginate" .}}
+				{{if not .Repos}}
+					<div class="empty-placeholder">
+						{{svg "octicon-repo" 48}}
+						<h2>{{ctx.Locale.Tr "org.repos.empty"}}</h2>
+						<p>{{ctx.Locale.Tr "org.repos.empty_description"}}</p>
+					</div>
+				{{else}}
+					{{template "shared/repo/list" .}}
+					{{template "base/paginate" .}}
+				{{end}}
 			</div>
 
 			{{if .ShowMemberAndTeamTab}}