Add nightly GitHub prerelease build (ZIP asset) via Actions

[masteradhoc]

Is your enhancement related to a problem? Please describe.

It would be useful to have an automated “nightly” prerelease on GitHub that packages the current default branch into a ZIP for testing and early adopters, without impacting the existing WordPress.org/SVN deploy workflow.

Proposed Solution

Add a new workflow .github/workflows/nightly.yml that runs on a nightly cron, builds the plugin, zips the build output (dist) into .zip, and publishes/updates a prerelease on GitHub under a fixed tag, e.g. nightly.

Designs

No response

Describe alternatives you've considered

No response

Please confirm that you have searched existing issues in this repository.

Yes

[jeffpaul]

Alternative idea, replicate the WP Playground action from the wp/ai repo that adds a Playground test link to all PRs as the more likely place folks would be looking to test: https://github.com/WordPress/ai/blob/develop/.github/workflows/pr-playground-preview.yml. If someone wants to test a nightly, they could build from the base branch.

[masteradhoc]

@jeffpaul yeah definately also a good idea - could be additionally or replace my idea.