fix(performance): reduce unnecessary reruns and improve dashboard responsiveness

[shruthikha]

Reduced unnecessary Streamlit reruns by removing forced st.rerun() calls.
Improved dashboard responsiveness by controlling background scan triggers.
Added optional auto-scan toggle and prevented redundant refresh cycles.
Result: smoother UI, reduced lag, and better caching efficiency.

[shruthikha]

Heyy!! I have tested these changes locally and made sure that it improves the UI responsiveness and reduced unnecessary reruns...

[Codex-Crusader]

Hello, Nice work and thank you for contributing

Have you checked other parts of the dashboard regarding minor exceptions or exception leaks and unassigned data for this?
Since a toggle might have been added but it affects other files too. so according to PEP8 coding standards (as mentioned in the contributing.md) these are also pre-requisites.

please do check and revert to us before we merge your branch.
thank you.

[Codex-Crusader]

Change 1 - Auto-scan checkbox: Widget is declared after it's read; move the st.sidebar.checkbox above the if block to avoid ordering fragility.

Change 2 - Removed st.rerun() after scan: This breaks the UI refresh — the comment above literally says a rerun is needed to pick up fresh data. Use st.fragment or a conditional rerun instead of removing it entirely.

Change 3 - Stale data st.info: Good direction, but pair it with a st.button("Refresh now") so the user has an actual way to act on the message.

Change 4 - "Load news feed" button: Removing st.rerun() here makes the button feel broken, session state is set but the news section won't render until the next unrelated interaction.

Change 5 - "Load live data" button: Same issue as above; the spinner below never triggers on the same click without a rerun.

General: Avoid emoji in source comments (# ❌) , encoding issues in some CI/editor setups. The overall strategy is inconsistent: some changes are solid UX improvements, but the rerun removals in changes 2, 4, and 5 trade correctness for perceived performance gains.

[shruthikha]

Heyyy!! Thanks for the detailed feedback

I've addressed all the requested changes:

-> Moved the auto-scan checkbox above its usage
->Restored necessary rerun behavior where required
-> Ensured "Load news feed" and "Load live data" buttons trigger UI updates correctly
-> Improved stale data handling with a user-triggered "Refresh now" button
->Standardized _scan_refresh_epoch updates using st.session_state for consistency
->Removed emoji from source comments

Please take another look when you have time. Happy to make further improvements if needed!!!

[Codex-Crusader]

All five points from my previous review have been addressed:

• Checkbox ordering - st.sidebar.checkbox is now declared before it's read
• Button reruns -st.rerun() restored on both "Load news feed" and "Load live data" buttons
• Stale data UX - st.info is now paired with a "Refresh now" button so users can act on it
• Epoch increment bug - all increments now consistently read from st.session_state instead of a stale local variable
• Emoji in comments - removed

CI passes on py3.11 and py3.12. Nice work, merging.
Congratulations on your first merge :)

[Codex-Crusader]

Hope to see more of your contributions as we go!
Do star the repo.