Basic UI of Dashboard

[Aryan0512398]

Issue: #136

⚠️ This PR is linked to a valid OpenCode issue.
PRs without an issue number may not be reviewed.

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Thank you for contributing to SubSentry 🚀
Please complete this template carefully to help mentors and bots review your PR efficiently.

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📌 Description

This PR implements the structural dashboard UI for SubSentry.
It introduces a reusable dashboard layout with a sidebar and top navigation, ensuring a clean separation between layout and feature-specific content.

The goal is to provide a consistent, scalable foundation for future dashboard features (subscriptions, analytics, ingestion) without requiring layout rewrites later.

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🧩 Issue Reference

Related Issue: #136

Note: Do NOT use words like Closes, Fixes, or Resolves.

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🛠️ What Did You Implement?

Please list the major things you worked on in this PR:

• Feature implementation
• UI changes
• API / backend logic
• Refactor / cleanup
• Documentation update
• Demo / setup task

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📁 Workspace Confirmation (MANDATORY)

Since all issues are Open for All, confirm the following:

• All changes are inside
  contributors/<your-github-username>/
• Base client/ files were copied from the main directory
• No files outside my personal workspace were modified

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🧪 Testing Performed

Please check what applies:

• Frontend runs locally without errors
• Backend server runs locally without errors
• APIs tested with valid inputs
• APIs tested with invalid / edge-case inputs
• No console errors or warnings

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📷 Screenshots / Demo

Attached screenshots show:

• Dashboard layout structure
• Sidebar and top navigation
• Dark-themed UI
• Empty content area reserved for future features

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✅ Final PR Checklist

Before submitting, ensure:

• This PR addresses only one issue
• Issue number is mentioned at the top
• Code is readable and well-structured
• No unnecessary files are included
• No sensitive data or .env files committed
• Commit messages follow project conventions
• PR title is clear and descriptive

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📎 Additional Notes for Reviewers

This PR intentionally avoids feature-specific UI and business logic.
It focuses only on building a clean, reusable dashboard structure as required by the issue.

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Thank you for contributing to SubSentry 💙
Your effort helps make this project better for everyone 🚀

[OpenGitBot]

Hey @Aryan0512398

This is not a valid Issue Number. Kindly recheck it!

[OpenGitBot]

Hey @Aryan0512398

Thanks for opening this PR 🚀. Mentor will review your pull request soon and till then, keep contributing and stay calm.

Thanks for contributing in OpenCode'25 ✨✨!

[Aryan-coder06]

Small but important: your changes edit base_files/after_issue_3, which is not allowed. Please move all updates into contributors//client only, then re-submit. We’ll re-review after that.