fix(events): use stable subscription ids and remove by id

[VolodymyrBg]

Replace index-based deletion with stable id matching in Producer.Start and assign ids from a monotonically increasing counter in Subscribe. This fixes incorrect removals after slice compaction while keeping behavior otherwise unchanged.

[eljobe]

Hey @VolodymyrBg, can you provide a testcase that would be failing before this change?
I haven't seen the issue you describe in the PR comment.

[VolodymyrBg]

Hey @VolodymyrBg, can you provide a testcase that would be failing before this change? I haven't seen the issue you describe in the PR comment.

added a test case

[eljobe]

Hey @VolodymyrBg, can you provide a testcase that would be failing before this change? I haven't seen the issue you describe in the PR comment.

added a test case

This looks very strange. Usually go tests go in a separate _test.go file.

[VolodymyrBg]

Hey @VolodymyrBg, can you provide a testcase that would be failing before this change? I haven't seen the issue you describe in the PR comment.

added a test case

This looks very strange. Usually go tests go in a separate _test.go file.

sh... really did a bad thing and didn't even notice this, sorry

[VolodymyrBg]

Hey @VolodymyrBg, can you provide a testcase that would be failing before this change? I haven't seen the issue you describe in the PR comment.

added a test case

This looks very strange. Usually go tests go in a separate _test.go file.

it was my copypaste mistake

[eljobe]

Thanks for the test, and the fix. This is clearly better.

Can you also switch your indentation in the test file to use tabs instead of spaces?

[VolodymyrBg]

Thanks for the test, and the fix. This is clearly better.

Can you also switch your indentation in the test file to use tabs instead of spaces?

Corrected