feat: add post button - [CU-869bfz11p]

[mostafahassan04]

This pull request introduces a new PostTweetDialog component to enable users to compose and post tweets from the sidebar.

[AhmedAmrNabil]

Task linked: CU-869bfz11p post button

[github-actions]

Testers Checklist

General

• Validation for every input
• Persistent try/catch blocks
• No lack of documentation
• Localization

Frontend

• Caching (if applicable)
• Responsiveness for all screens
• Loading indicators & skeleton loaders
• Optimistic loading (if applicable)
• No warnings in console

[github-actions]

Unit Tests Coverage Report

Coverage after merging feat/post-button into dev will be

78.68%

Coverage Report for Changed Files

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
app/components/SideBar/Left
index.vue	59.70%	75%	18.18%	63.89%	125, 125, 125, 134, 137, 142, 145, 151, 21–22, 28, 30, 30, 30–31, 33, 76, 87
app/components/tweet/composer
PostTweetDialog.vue	94.44%	75%	100%	100%	17