feat: implement keyboard shortcuts and help UI modal #28

[mohitmeena3883]

program: gssoc

description

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🔗 Related Issue

Closes #28

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📄 What does this PR do?

Implemented the requested keyboard shortcuts and accessibility indicators for the chat interface:

• Ctrl/Cmd + Enter: Sends the currently typed chat message if the input textarea is focused.
• Esc: Clears the chat text input when active, or closes the shortcuts modal window.
• Ctrl/Cmd + K: Globally shifts document focus straight to the chat textarea field.
• Added a floating ❓ (HelpCircle) UI toggle button inside the chat panel input container that opens an accessible modal popup detailing all available keyboard configurations.

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📁 Type of Change

• 🐛 Bug fix
• ✨ New feature
• 🔧 Refactor / code cleanup
• 📄 Documentation update
• 🎨 UI / styling change
• ⚙️ CI / tooling / config change

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🧪 How was this tested?

• Ran the backend locally (uvicorn app.main:app --reload)
• Ran the frontend locally (npm run dev inside /frontend)
• Tested the affected API endpoints manually
• Added / updated tests

⚠️ Anything to flag for reviewers?

None. The shortcuts use native browser event handling and properly prevent standard browser overrides (like stopping Ctrl+K from opening the browser address bar).

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🧼 Self-Review Checklist

• My branch is based on **dev**, not main
• I have not added any secrets / API keys
• I have not modified main branch or any HuggingFace deployment config
• My code follows the existing style (no unnecessary formatting changes)
• I have updated relevant docs / comments if needed