fix: show filebrowser subdomain link on stacks page

Protected stacks like filebrowser have no .felhom.yml or app.yaml,
so the subdomain lookup found nothing. Added well-known subdomain
fallback map for programmatically managed protected stacks.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/internal/web/handlers.go

@@ -20,6 +20,12 @@ import (
 )
 
 
+// protectedStackSubdomains maps programmatically managed protected stacks
+// to their well-known subdomains (these stacks have no .felhom.yml or app.yaml).
+var protectedStackSubdomains = map[string]string{
+	"filebrowser": "files",
+}
+
 // StorageBarInfo holds data for rendering a storage usage bar on dashboard/monitoring.
 type StorageBarInfo struct {
 	Label        string  // e.g., "USB HDD 1TB", "SYS Storage 350G"
@@ -182,7 +188,11 @@ func (s *Server) dashboardHandler(w http.ResponseWriter, r *http.Request) {
 				}
 			}
 		}
-		subdomains[stack.Name] = stack.Meta.Subdomain
+		if stack.Meta.Subdomain != "" {
+			subdomains[stack.Name] = stack.Meta.Subdomain
+		} else if sd, ok := protectedStackSubdomains[stack.Name]; ok {
+			subdomains[stack.Name] = sd
+		}
 	}
 	data["Subdomains"] = subdomains
 
@@ -217,7 +227,7 @@ func (s *Server) stacksHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	data["StorageLabels"] = storageLabels
 
-	// Build effective subdomain lookup (stored env > metadata fallback)
+	// Build effective subdomain lookup (stored env > metadata > well-known fallback)
 	subdomains := make(map[string]string)
 	for _, stack := range s.stackMgr.GetStacks() {
 		if stack.Deployed {
@@ -228,7 +238,11 @@ func (s *Server) stacksHandler(w http.ResponseWriter, r *http.Request) {
 				}
 			}
 		}
-		subdomains[stack.Name] = stack.Meta.Subdomain
+		if stack.Meta.Subdomain != "" {
+			subdomains[stack.Name] = stack.Meta.Subdomain
+		} else if sd, ok := protectedStackSubdomains[stack.Name]; ok {
+			subdomains[stack.Name] = sd
+		}
 	}
 	data["Subdomains"] = subdomains