fix: prevent node width expansion when content overflows after resize

Proxmox nodes with container_mode=false fell through both width conditions
in deserializeApiNode and got no explicit width on reload, causing RF to
auto-size to content width and ignoring the user's manual resize.

- canvasSerializer: unified width restore logic — saved width applies to all
  node types; proxmox container_mode defaults (300x200) only kick in when
  no saved width exists
- BaseNode: add overflow-hidden + min-w-0 to properties row so truncate
  actually clips long values instead of expanding the node

frontend/src/components/canvas/nodes/BaseNode.tsx

@@ -77,7 +77,7 @@ export function BaseNode({ id, data, selected, icon: typeIcon, width, height }:
       <Handle type="target" position={Position.Top} id="top-t" style={{ opacity: 0, width: 12, height: 12 }} />
 
       {/* Main row */}
-      <div className="flex flex-row items-center gap-2.5 px-2.5 py-2">
+      <div className="flex flex-row items-center gap-2.5 px-2.5 py-2 min-w-0 overflow-hidden">
         {/* Icon */}
         <div
           className="flex items-center justify-center w-7 h-7 rounded-md shrink-0"
@@ -115,14 +115,14 @@ export function BaseNode({ id, data, selected, icon: typeIcon, width, height }:
       {visibleProperties && visibleProperties.length > 0 && (
         <>
           <div style={{ height: 1, background: `${colors.border}44`, margin: '0 8px' }} />
-          <div className="flex flex-col gap-1 px-2.5 py-1.5">
+          <div className="flex flex-col gap-1 px-2.5 py-1.5 overflow-hidden">
             {visibleProperties.map((prop) => {
               const Icon = resolvePropertyIcon(prop.icon)
               return (
-                <div key={prop.key} className="flex items-center gap-1 font-mono text-[10px]" style={{ color: theme.colors.nodeSubtextColor }}>
+                <div key={prop.key} className="flex items-center gap-1 font-mono text-[10px] min-w-0 overflow-hidden" style={{ color: theme.colors.nodeSubtextColor }}>
                   {Icon && <Icon size={9} className="shrink-0" />}
                   <span className="truncate max-w-[60px] shrink-0" title={prop.key}>{prop.key}</span>
-                  <span className="truncate" title={prop.value}>· {prop.value}</span>
+                  <span className="truncate min-w-0" title={prop.value}>· {prop.value}</span>
                 </div>
               )
             })}