Feat v0.6.17 bug fixes & welcome logic (#52)

Fix broken folder creation (sw.prompt), team member add (envelope unwrap),
dropdown overflow (min-width:max-content), welcome auto-disable when
surfaces installed, zero default bundled packages.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/pages/pages.go

@@ -494,6 +494,10 @@ func (e *Engine) RegisterPageRoutes(base *gin.RouterGroup, mw PageRouteMiddlewar
 				continue
 			}
 			handler := e.RenderSurface(s.ID)
+			// Welcome auto-redirects to / when extension surfaces exist
+			if s.ID == "welcome" {
+				handler = e.welcomeRedirectIfSurfaces(handler)
+			}
 			registerRoutes(group, s, handler)
 		}