chore: add automatic changelogs and release management

[VojtaM39]

This PR modifies the release process so we don't have to do a manual bump and manually write changelogs.

The release happens by manually dispatching action with either specified bump type or auto bump, the action then creates release commit under service account, publishes to npm and prepends changelog.

To see how the changelog will look, check the dry run action.

Closes: #705

[VojtaM39]

@B4nan
Could you also please check? We wanted to add a simple way to generate changelogs and simplify releases. This approach is heavily inspired from https://github.com/apify/apify-sdk-js/blob/master/.github/workflows/release.yaml.

[B4nan]

Lookg good, few nits claude found follow.

Outside the diff: docs/agents/git-and-prs.md (lines 23-24) still says latest is published when a GitHub Release is published, and tells authors to bump package.json because before-beta-release.cjs fails otherwise. Both go away with this PR, and every agent-authored PR reads that file. It should point to RELEASING.md instead.

Also: the first auto dispatch computes 3.1.0, and the only commit driving the minor is #683 (feat: Add AGENTS.md). Nothing user-facing changed there, so it should have been chore or docs. Either dispatch patch the first time or accept 3.1.0.

[VojtaM39]

@bliuchak do we still want to release as 3.1.0?

Since #683 (comment) should be chore, according to semver we should release 3.0.1.

[B4nan]

Just pick the patch bump manually. Tbh, I am using explicit bumps all the time, never got used to the full automation. Some commits should get to the changelog, they are not bugs, yet they don't deserve a feature bump either. I like to stay in control.

[bliuchak]

@VojtaM39 Well, I don't know the details of how this new "release" feature works right now. But I was expecting these changes (see list below) to be more minor than a patch.

List of things:

• Migrate tests from JS to Typescript
• Replace mocha with Vitest

I admit they're not adding any new functionality directly to proxy-chain, but I don't consider them small changes. We're replacing the entire test library and rewriting the tests in a different language.

Does it make sense?

P.S. I don't insist on a minor release. If we believe that the patch is better, let's do a patch. I don't have a strong opinion here.

[B4nan]

Migrate tests from JS to Typescript
Replace mocha with Vitest

If you ask me, changelogs are for users, not maintainers, and none of this is user facing, to me those should not be part of the changelog. Both should have test commit type.

[VojtaM39]

I also don't have a strong opinion, I think minor is fine. Just wanted to check 👍

[B4nan]

In general, people are more likely to update to a patch bump, since all it should consist of is bug fixes, and who doesn't like bug fixes? But feature releases are a different story, minor bumps might see slower adoption (and also higher expectations, people might be sad seeing a minor that doesn't have any user facing changes 🙃).

But yes, it's surely not that important, do as you wish :]