fix: replace bg-accent with neutral backgrounds on code/kbd elements

bg-accent maps to bright cyan (#22d3ee) in Tailwind v4 — wrong for
code elements and keyboard shortcut badges. This was a recurring issue
across the app where every backticked term glowed cyan.

- Code blocks: bg-accent → bg-code (#14161e)
- Inline code: bg-accent → bg-white/[0.08] (subtle neutral tint)
- Kbd badges: bg-accent → bg-white/[0.08]
- AI chat markdown: same fixes in MarkdownContent.tsx

Cyan remains reserved for interactive elements (buttons, active nav,
links) per the design system.

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

frontend/src/components/procedural-editor/StepEditor.tsx

@@ -112,7 +112,7 @@ export function StepEditor({ step, stepNumber, onUpdate, onCollapse, availableVa
                 <button
                   key={v.variable_name}
                   onClick={() => onUpdate({ description: (step.description || '') + `[VAR:${v.variable_name}]` })}
-                  className="rounded bg-accent/50 px-1.5 py-0.5 font-mono text-[10px] text-muted-foreground hover:bg-accent hover:text-muted-foreground"
+                  className="rounded bg-white/[0.06] px-1.5 py-0.5 font-mono text-[10px] text-muted-foreground hover:bg-white/[0.10] hover:text-muted-foreground"
                 >
                   {v.variable_name}
                 </button>

frontend/src/components/tree-editor/NodeEditorModal.tsx

@@ -86,7 +86,7 @@ export function NodeEditorModal({ node, onClose, isNewNode = false }: NodeEditor
     <Modal isOpen={true} onClose={onClose} title={getTitle()} size="lg" footer={footerContent} allowFullScreen={true}>
       {/* Node ID display */}
       <div className="mb-4 text-xs text-muted-foreground">
-        Node ID: <code className="rounded bg-accent px-1 py-0.5">{node.id}</code>
+        Node ID: <code className="rounded bg-white/[0.08] px-1 py-0.5">{node.id}</code>
       </div>
 
       {/* Validation errors */}

frontend/src/components/tree-editor/code-mode/SyntaxHelpPanel.tsx

@@ -103,7 +103,7 @@ function Row({ label, code }: { label: string; code: string }) {
   return (
     <div className="flex items-center justify-between py-0.5">
       <span className="text-muted-foreground">{label}</span>
-      <code className="rounded bg-accent px-1 py-0.5 text-[10px] text-muted-foreground">{code}</code>
+      <code className="rounded bg-white/[0.08] px-1 py-0.5 text-[10px] text-muted-foreground">{code}</code>
     </div>
   )
 }

frontend/src/components/ui/MarkdownContent.tsx

@@ -43,7 +43,7 @@ export function MarkdownContent({ content, className }: MarkdownContentProps) {
             return (
               <code
                 className={cn(
-                  'block rounded bg-accent p-3 font-mono text-sm overflow-x-auto',
+                  'block rounded bg-code p-3 font-mono text-sm text-foreground overflow-x-auto',
                   className
                 )}
                 {...props}
@@ -54,7 +54,7 @@ export function MarkdownContent({ content, className }: MarkdownContentProps) {
           }
           return (
             <code
-              className="rounded bg-accent px-1.5 py-0.5 font-mono text-sm"
+              className="rounded bg-white/[0.08] px-1.5 py-0.5 font-mono text-sm text-secondary"
               {...props}
             >
               {children}
@@ -63,7 +63,7 @@ export function MarkdownContent({ content, className }: MarkdownContentProps) {
         },
         // Style code blocks (pre)
         pre: ({ children }) => (
-          <pre className="mb-3 overflow-x-auto rounded bg-accent p-0 last:mb-0">
+          <pre className="mb-3 overflow-x-auto rounded bg-code p-0 last:mb-0">
             {children}
           </pre>
         ),

frontend/src/pages/MaintenanceFlowDetailPage.tsx

@@ -193,7 +193,7 @@ export default function MaintenanceFlowDetailPage() {
                   : <AlertCircle className="h-3 w-3" />}
                 {schedule.is_active ? 'Active' : 'Paused'}
               </span>
-              <code className="rounded bg-accent px-1.5 py-0.5 text-[0.8125rem] text-foreground">
+              <code className="rounded bg-white/[0.08] px-1.5 py-0.5 text-[0.8125rem] text-foreground">
                 {schedule.cron_expression}
               </code>
               <span className="text-muted-foreground">({schedule.timezone})</span>

frontend/src/pages/TreeNavigationPage.tsx

@@ -954,7 +954,7 @@ export function TreeNavigationPage() {
                     <div key={index}>
                       <p className="mb-1 text-xs text-muted-foreground">{cmd.label}</p>
                       <div className="group relative">
-                        <code className="block rounded bg-accent p-2 pr-8 text-sm font-mono">
+                        <code className="block rounded bg-code p-2 pr-8 text-sm font-mono">
                           {cmd.command}
                         </code>
                         <button
@@ -1076,7 +1076,7 @@ export function TreeNavigationPage() {
                 <div className="space-y-1">
                   {currentNode.commands.map((cmd, index) => (
                     <div key={index} className="group relative">
-                      <code className="block rounded bg-accent p-2 pr-8 text-sm font-mono">
+                      <code className="block rounded bg-code p-2 pr-8 text-sm font-mono">
                         {cmd}
                       </code>
                       <button
@@ -1302,23 +1302,23 @@ export function TreeNavigationPage() {
         <div className="space-y-3 text-sm">
           <div className="flex items-center justify-between">
             <span className="text-muted-foreground">Select option</span>
-            <span className="rounded bg-accent px-2 py-0.5 font-mono text-xs text-foreground">1-9</span>
+            <span className="rounded bg-white/[0.08] px-2 py-0.5 font-mono text-xs text-foreground">1-9</span>
           </div>
           <div className="flex items-center justify-between">
             <span className="text-muted-foreground">Go back</span>
-            <span className="rounded bg-accent px-2 py-0.5 font-mono text-xs text-foreground">Esc</span>
+            <span className="rounded bg-white/[0.08] px-2 py-0.5 font-mono text-xs text-foreground">Esc</span>
           </div>
           <div className="flex items-center justify-between">
             <span className="text-muted-foreground">Continue / Complete</span>
-            <span className="rounded bg-accent px-2 py-0.5 font-mono text-xs text-foreground">Enter</span>
+            <span className="rounded bg-white/[0.08] px-2 py-0.5 font-mono text-xs text-foreground">Enter</span>
           </div>
           <div className="flex items-center justify-between">
             <span className="text-muted-foreground">Focus notes</span>
-            <span className="rounded bg-accent px-2 py-0.5 font-mono text-xs text-foreground">Tab</span>
+            <span className="rounded bg-white/[0.08] px-2 py-0.5 font-mono text-xs text-foreground">Tab</span>
           </div>
           <div className="flex items-center justify-between">
             <span className="text-muted-foreground">Show shortcuts</span>
-            <span className="rounded bg-accent px-2 py-0.5 font-mono text-xs text-foreground">?</span>
+            <span className="rounded bg-white/[0.08] px-2 py-0.5 font-mono text-xs text-foreground">?</span>
           </div>
         </div>
       </Modal>

frontend/src/pages/admin/InviteCodesPage.tsx

@@ -119,7 +119,7 @@ export function InviteCodesPage() {
       key: 'code',
       header: 'Code',
       render: (c) => (
-        <code className="rounded bg-accent px-2 py-1 text-sm font-mono text-muted-foreground">{c.code}</code>
+        <code className="rounded bg-white/[0.08] px-2 py-1 text-sm font-mono text-muted-foreground">{c.code}</code>
       ),
     },
     {