feat: Support bigger font size in dashboard (#10974)

# Pull Request Template

## Description

Fixes
https://linear.app/chatwoot/issue/CW-4091/accessibility-improvement-support-bigger-font-size-for-the-dashboard

## Type of change

- [x] New feature (non-breaking change which adds functionality)

## How Has This Been Tested?

### **Loom video**

https://www.loom.com/share/1ab781859fa748a5ad54aacbacd127b4?sid=a7dd9164-a6de-462f-bff7-1b25e9c55b4f

## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

app/javascript/dashboard/components/widgets/conversation/ConversationSidebar.vue

@@ -53,7 +53,7 @@ const showCopilotTab = computed(() =>
 
 <template>
   <div
-    class="ltr:border-l rtl:border-r border-n-weak h-full overflow-hidden z-10 min-w-[320px] w-[320px] 2xl:min-w-96 2xl:w-96 flex flex-col bg-n-background"
+    class="ltr:border-l rtl:border-r border-n-weak h-full overflow-hidden z-10 w-80 min-w-80 2xl:min-w-96 2xl:w-96 flex flex-col bg-n-background"
   >
     <div v-if="showCopilotTab" class="p-2">
       <TabBar