Fix mobile white screen: stop Outlet Date.now() remount loop (#54) (#56)

## Summary

- Follow-up for #54 (localStorage guard in #55 did not fix mobile white screen)
- Confirmed in production bundle: `ProtectedRoutes` rendered `<Outlet key={Date.now()} />`
- That remounts the entire authenticated tree on **every** parent re-render (account fetch, WebSocket connect/status, conversations, messages)
- On mobile this shows as: brief UI flash → solid white page (matches screen recording)
- Also memoize styled-components theme in `GlobalThemeWrapper` so `ParticleBackground` does not tear down/restart its canvas on unrelated re-renders

## Evidence

Production JS currently contains:
```js
e?(0,ma.jsx)(a.sv,{},Date.now()):(0,ma.jsx)(a.C5,{to:"/signin/",replace:!0})
```
i.e. authenticated → `<Outlet key={Date.now()} />`

## Test plan

- [ ] Mobile Vivaldi/Chrome: sign in on hesychia.ai → dashboard stays visible (header, conversations toggle, input)
- [ ] Pull-to-refresh while logged in → UI returns and stays
- [ ] Desktop login still works; switching conversations / WS reconnect does not blank the page
- [ ] Open mobile menu / Conversations sidebar still worksReviewed-on: #56

llm-fe/src/App.tsx

@@ -34,7 +34,7 @@ const ProtectedRoutes = () => {
   if (!authenticated) return <Navigate to='/signin/' replace />
   //if(!needsNewPassword) return <Navigate to='/password_reset/' replace/>
 
-  return <Outlet key={Date.now()} />
+  return <Outlet />
 }
 
 

llm-fe/src/llm-fe/components/GlobalThemeWrapper/GlobalThemeWrapper.tsx

@@ -1,4 +1,4 @@
-import React from 'react';
+import React, { useMemo } from 'react';
 import { ThemeProvider } from 'styled-components';
 import { useMaterialUIController } from '../../ui-kit/context';
 import palettes from '../../ui-kit/assets/theme/base/palettes';
@@ -11,14 +11,13 @@ const GlobalThemeWrapper = ({ children }: GlobalThemeWrapperProps): JSX.Element
     const [controller] = useMaterialUIController();
     const { themeColor, darkMode } = controller;
 
-    // Default to blue if themeColor is not found
+    // Stable theme ref — ParticleBackground restarts its canvas whenever theme identity changes.
+    const theme = useMemo(() => {
         const selectedPalette = palettes[themeColor as keyof typeof palettes] || palettes.blue;
-
-    const theme = {
+        return {
             main: selectedPalette.main,
             focus: selectedPalette.focus,
             darkMode: darkMode,
-        // Add other global theme variables here if needed
             colors: {
                 background: darkMode ? '#1a2035' : '#f0f2f5',
                 text: darkMode ? '#ffffff' : '#344767',
@@ -26,6 +25,7 @@ const GlobalThemeWrapper = ({ children }: GlobalThemeWrapperProps): JSX.Element
                 cardBorder: darkMode ? 'rgba(255, 255, 255, 0.1)' : 'rgba(0, 0, 0, 0.05)',
             }
         };
+    }, [themeColor, darkMode]);
 
     return (
         <ThemeProvider theme={theme}>