Add Network Sentinel plugin

[KrishGaur1354]

Add Network Sentinel to Plugin Store

Monitor network quality and track connection performance with live ping display, latency charts, and network history tracking for Steam Deck.
It helps users visualize their connection health in real time by showing latency trends, packet stability, and historical data directly in the Decky interface.

Task Checklist

Developer

• I am the original author or an authorized maintainer of this plugin.
• I have abided by the licenses of the libraries I am utilizing, including attaching license notices where appropriate.

Plugin

• I have verified that my plugin works properly on the Stable and Beta update channels of SteamOS.
• I have verified my plugin is unique or provides more/alternative functionality to a plugin already on the store.

Backend

• No: I am using a custom backend other than Python.
• No: I am using a tool or software from a 3rd party FOSS project that does not have its dependencies statically linked.
• No: I am using a custom binary that has all of its dependencies statically linked.

Community

• I have tested and left feedback on two other pull requests for new or updating plugins.
• I have commented links to my testing report in this PR.

Testing

• Tested by a third party on SteamOS Stable or Beta update channel.

[EMERALD0874]

@KrishGaur1354 Your PR does not conform to existing PR templates. Please see the latest plugin addition template here and ensure it is filled out correctly per the Markdown comments.

[KrishGaur1354]

@KrishGaur1354 Your PR does not conform to existing PR templates. Please see the latest plugin addition template here and ensure it is filled out correctly per the Markdown comments.

Yeah, my bad @EMERALD0874. I've updated it to the latest plugin addition template as per the guidelines mention in it.

[EMERALD0874]

Please properly remove the irrelevant line in the Testing section per the Markdown comment above that section.

[KrishGaur1354]

I’ve removed the unnecessary line in testing. Please let me know if anything else needs adjustment.

[EMERALD0874]

• Please update "Hypothetical Plugin Developer" in your LICENSE file to your name.
• Please remove the /assets folder or the logo within it if you aren't using it.
• Please remove the /defaults folder if you aren't using it.
• Please remove the /backend folder if you aren't using it. This will break deployment.

[KrishGaur1354]

@EMERALD0874 I've made the requested changes in the Repo

[EMERALD0874]

You need to update the submodule in your PR to this repo so we can see your changes.

[github-actions]

This pull request is stale as no updates or testing reports have been posted within the last 7 days. Please ensure you are actively recruiting testers or resolving the issues discussed. If you do not remove the stale label or comment, this will be closed in 7 days. Please close this pull request if you need more time to resolve issues so we can keep our repo healthy.

[KrishGaur1354]

@EMERALD0874 I have updated the submodule on the recent commit changes