feat(branding): customize Gita platform experience

Assisted-by: Codex:GPT-5

routers/web/auth/auth.go

@@ -40,7 +40,7 @@ import (
 )
 
 const (
-	tplSignIn         templates.TplName = "user/auth/signin"          // for sign in page
+	tplSignIn         templates.TplName = "home"                      // sign in is part of the landing page
 	tplSignUp         templates.TplName = "user/auth/signup"          // for sign up page
 	TplActivate       templates.TplName = "user/auth/activate"        // for activate user
 	TplActivatePrompt templates.TplName = "user/auth/activate_prompt" // for showing a message for user activation
@@ -254,9 +254,10 @@ func prepareSignInPageData(ctx *context.Context) (ret preparedSignInData) {
 	ctx.Data["Title"] = ctx.Tr("sign_in")
 	ctx.Data["OAuth2Providers"] = ret.oauth2Providers
 	ctx.Data["Title"] = ctx.Tr("sign_in")
-	ctx.Data["SignInLink"] = setting.AppSubURL + "/user/login"
+	ctx.Data["SignInLink"] = setting.AppSubURL + "/"
 	ctx.Data["PageIsSignIn"] = true
 	ctx.Data["PageIsLogin"] = true
+	ctx.Data["PageIsHome"] = true
 	ctx.Data["EnableSSPI"] = ret.enableSSPI
 
 	prepareCommonAuthPageData(ctx, CommonAuthOptions{
@@ -265,6 +266,11 @@ func prepareSignInPageData(ctx *context.Context) (ret preparedSignInData) {
 	return ret
 }
 
+// PrepareSignInPageData exposes the shared sign-in data for the landing page.
+func PrepareSignInPageData(ctx *context.Context) {
+	prepareSignInPageData(ctx)
+}
+
 // SignIn render sign in page
 func SignIn(ctx *context.Context) {
 	if performAutoLogin(ctx) {