No event emitted when a stream is paused

[Jaydbrown]

Description

The protocol supports pausing streams, but the pause_stream function does not emit an event. This makes it impossible for off-chain indexers and the frontend SDK to track the exact moment a stream was paused without polling the contract state.

Suggested Fix

1. Define a new StreamPaused event containing the stream_id, the caller address, and the timestamp.
2. Emit this event at the end of the pause_stream function execution.
3. Ensure the unpause_stream function also emits a corresponding StreamUnpaused event.

[Juwon345]

I would like to work on this issue

[grantfox-oss]

🦊 GrantFox — @Juwon345 has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #74)
2. Your PR will be reviewed by the conduit-protocol maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🦊 GrantFox — @Juwon345 has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #74)
2. Your PR will be reviewed by the conduit-protocol maintainers

Good luck! Track your progress on GrantFox.