feat(pages): Route custom domains to landing page

Custom domains configured in Pages settings now route directly
to the repository landing page, in addition to subdomain routing.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

routers/web/web.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	auth_model "code.gitea.io/gitea/models/auth"
+	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/perm"
 	"code.gitea.io/gitea/models/unit"
 	"code.gitea.io/gitea/modules/git"
@@ -302,7 +303,7 @@ var optSignInFromAnyOrigin = verifyAuthWithOptions(&common.VerifyOptions{Disable
 
 // registerWebRoutes register routes
 func registerWebRoutes(m *web.Router) {
-	// Check for Pages subdomain requests first
+	// Check for Pages subdomain and custom domain requests first
 	m.Use(func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 			host := req.Host
@@ -310,6 +311,7 @@ func registerWebRoutes(m *web.Router) {
 			if idx := strings.Index(host, ":"); idx > 0 {
 				host = host[:idx]
 			}
+
 			// Check if this is a subdomain of our main domain
 			mainDomain := setting.Domain
 			if strings.HasSuffix(host, "."+mainDomain) {
@@ -324,6 +326,17 @@ func registerWebRoutes(m *web.Router) {
 						return
 					}
 				}
+			} else if host != mainDomain && host != "www."+mainDomain {
+				// Check if this is a custom domain for Pages
+				domain, err := repo_model.GetPagesDomainByDomain(req.Context(), host)
+				if err == nil && domain != nil && domain.Verified {
+					ctx := context.GetWebContext(req.Context())
+					if ctx != nil {
+						log.Trace("Pages custom domain request: %s -> repo %d", host, domain.RepoID)
+						pages.ServeLandingPage(ctx)
+						return
+					}
+				}
 			}
 			next.ServeHTTP(w, req)
 		})