Optimize the dashboard (#32990)

before:

![image](https://github.com/user-attachments/assets/d0b432e4-a521-4540-a489-d18b9c265674)

after:

![image](https://github.com/user-attachments/assets/dbb8b387-d150-41e2-b12b-f9d8450e36d7)
-----

![image](https://github.com/user-attachments/assets/40dcd71e-344b-4043-9811-77227c71aed9)
-----

Optimize the dashboard by adding welcoming messages or quick action
entry points (such as adding a new repository or organization) to ensure
that new users are not greeted by a blank page upon logging in.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/user/dashboard/dashboard.tmpl

@@ -5,7 +5,11 @@
 		<div class="flex-container-main">
 			{{template "base/alert" .}}
 			{{template "user/heatmap" .}}
-			{{template "user/dashboard/feeds" .}}
+			{{if .Feeds}}
+				{{template "user/dashboard/feeds" .}}
+			{{else}}
+				{{template "user/dashboard/guide" .}}
+			{{end}}
 		</div>
 		{{template "user/dashboard/repolist" .}}
 	</div>

templates/user/dashboard/guide.tmpl

@@ -0,0 +1,10 @@
+<div class="tw-text-center tw-p-8">
+	{{svg "octicon-package" 24 "tw-text-placeholder-text"}}
+	<h3 class="tw-my-4">{{ctx.Locale.Tr "home.guide_title"}}</h3>
+	<p class="tw-text-placeholder-text">{{ctx.Locale.Tr "home.guide_desc"}}</p>
+	<div>
+		<a href="{{AppSubUrl}}/explore/repos">{{ctx.Locale.Tr "home.explore_repos"}}</a>
+		<span>·</span>
+		<a href="{{AppSubUrl}}/explore/users">{{ctx.Locale.Tr "home.explore_users"}}</a>
+	</div>
+</div>

templates/user/dashboard/repolist.tmpl

@@ -5,6 +5,10 @@ const data = {
 	isMirrorsEnabled: {{.MirrorsEnabled}},
 	isStarsEnabled: {{not .IsDisableStars}},
 
+	canCreateMigrations: {{not .DisableMigrations}},
+
+	textNoOrg: {{ctx.Locale.Tr "home.empty_org"}},
+	textNoRepo: {{ctx.Locale.Tr "home.empty_repo"}},
 	textRepository: {{ctx.Locale.Tr "repository"}},
 	textOrganization: {{ctx.Locale.Tr "organization"}},
 	textMyRepos: {{ctx.Locale.Tr "home.my_repos"}},