V2: Design Navbar (#4017)

# Description of Changes

- Changed the navbar styling to include all the icons that were on our
figma design
- Added a new link to our index.html to include the MUI symbols. 
- I chose to keep the automate and read icons the same as they were
already because I feel as though they make more sense

```
<link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Material+Symbols+Outlined:opsz,wght,FILL,GRAD@24,700,0,0" />
```
---

figma vs app dark
<img width="422" height="1038" alt="Screenshot 2025-07-21 at 5 44 19 PM"
src="https://github.com/user-attachments/assets/15d5583f-ce3c-418f-81c6-6e6022f5f4d0"
/>

figma vs app light
<img width="244" height="926" alt="Screenshot 2025-07-21 at 5 57 27 PM"
src="https://github.com/user-attachments/assets/c855d02b-20ee-4ccf-af1f-a3c1a4c2a154"
/>



## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [x] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [x] I have performed a self-review of my own code
- [x] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [x] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [x] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

frontend/src/pages/HomePage.tsx

@@ -70,7 +70,7 @@ function HomePageContent() {
   }, [clearToolSelection]);
 
   const handleReaderToggle = useCallback(() => {
-    setReaderMode(!readerMode);
+    setReaderMode(true);
   }, [readerMode]);
 
   const handleViewChange = useCallback((view: string) => {
@@ -104,7 +104,7 @@ function HomePageContent() {
 
       {/* Left: Tool Picker or Selected Tool Panel */}
       <div
-        className={`h-screen flex flex-col overflow-hidden bg-[var(--bg-surface)] border-r border-[var(--border-subtle)] transition-all duration-300 ease-out ${isRainbowMode ? rainbowStyles.rainbowPaper : ''}`}
+        className={`h-screen flex flex-col overflow-hidden bg-[var(--bg-toolbar)] border-r border-[var(--border-subtle)] transition-all duration-300 ease-out ${isRainbowMode ? rainbowStyles.rainbowPaper : ''}`}
         style={{
           width: sidebarsVisible && !readerMode ? '14vw' : '0',
           padding: sidebarsVisible && !readerMode ? '0.5rem' : '0'
@@ -163,9 +163,11 @@ function HomePageContent() {
       {/* Main View */}
       <Box
         className="flex-1 h-screen min-w-80 relative flex flex-col"
-        style={{
-          backgroundColor: 'var(--bg-background)'
-        }}
+        style={
+          isRainbowMode
+            ? {} // No background color in rainbow mode
+            : { backgroundColor: 'var(--bg-background)' }
+        }
       >
         {/* Top Controls */}
         <TopControls