fix: prevent confirming state from immediately reverting in stream creation

[Horlarmmy]

Problem

After successfully submitting a stream creation, the UI was supposed to show a "Finalizing Stream..." state for 2 seconds before navigating to the dashboard. However, the finally block in the handleSubmit function was executing synchronously immediately after the try block completed, resetting setLoading(false) and setTxState("idle") before React could even render the confirming state.

This caused the button to flash past "Finalizing Stream..." and instantly revert to "Start Streaming", creating a glitchy user experience.

Root Cause

In create-stream-content.tsx:179-194, the finally block at lines 190-193 was placed outside the setTimeout callback, causing it to execute immediately after the async operation completed rather than waiting for the 2-second delay.

Solution

Moved the state reset logic from the finally block to the appropriate locations:

1. Success path: Moved setLoading(false) and setTxState("idle") inside the setTimeout callback, just before router.push("/dashboard"). This ensures the confirming state persists for the full 2 seconds before cleaning up and navigating.

2. Error path: Added the same state reset to the catch block so loading state is properly cleared on failure.

Changes

• frontend/src/app/streams/create/create-stream-content.tsx:179-194
  • Removed the finally block
  • Added state cleanup in setTimeout callback (success path)
  • Added state cleanup in catch block (error path)

Testing

All existing tests pass (286/286 across 32 test files). The change is minimal and focused on the state management timing, which is now correctly handled.

Impact

Fixes a visibly glitchy state transition on the primary stream-creation flow, improving the user experience by ensuring the "Finalizing Stream..." message is visible for the intended duration.

Closes #1231