fix: improve workspace manager navigation and sizing

frontend/src/shell/WorkspaceManager.tsx

@@ -2,6 +2,7 @@ import { useMemo, useState } from "react";
 import { useQuery, useQueryClient } from "@tanstack/react-query";
 import {
   AlertCircle,
+  ArrowLeft,
   CheckCircle2,
   ClipboardCheck,
   FlaskConical,
@@ -214,9 +215,18 @@ export function WorkspaceManager({ open, onClose }: { open: boolean; onClose: ()
     <Dialog open={open} onOpenChange={(nextOpen) => { if (!nextOpen) close(); }}>
       <DialogContent
         showCloseButton={false}
-        className="h-[70vh] w-[94vw] max-h-[90vh] max-w-[94vw] grid-rows-[auto_minmax(0,1fr)] gap-0 overflow-hidden p-0 sm:w-[70vw] sm:max-w-[94vw]"
+        className="h-[86vh] w-[94vw] max-h-[92vh] max-w-[94vw] grid-rows-[auto_minmax(0,1fr)] gap-0 overflow-hidden p-0 sm:w-[70vw] sm:max-w-[94vw]"
       >
         <DialogHeader className="border-b border-border/70 px-6 pb-4 pt-5 pr-12">
+          <Button
+            type="button"
+            size="sm"
+            variant="link"
+            className="w-fit px-0"
+            onClick={close}
+          >
+            <ArrowLeft />Back to main page
+          </Button>
           <DialogTitle>Workspace management</DialogTitle>
           <DialogDescription>
             Read, validate, and complete the runtime configuration of workspaces supplied by the installation repository.
@@ -251,7 +261,7 @@ export function WorkspaceManager({ open, onClose }: { open: boolean; onClose: ()
             </div>
           </nav>
 
-          <main className="min-w-0 overflow-y-auto px-6 py-5">
+          <main className="min-h-0 min-w-0 overflow-y-auto overscroll-contain px-6 py-5">
             {notice && (
               <p role="status" className="mb-4 flex items-center gap-2 rounded-md border border-border bg-muted/50 px-3 py-2 text-sm">
                 <CheckCircle2 className="size-4 text-primary" />{notice}