Walkthrough

This PR has no in-app screen — it changes a file GitHub reads when someone clicks "New pull request", and a workflow that runs on GitHub's side after the PR is opened. The Dentolize clinic app itself (the thing running at the sandbox URL for this branch) is completely unaffected; there's nothing new to click through inside it. Instead, this walkthrough renders the actual file content and the actual workflow-generated PR comment format so you can see exactly what changes.

1. Opening a new PR now shows this

When someone opens a new pull request against this repo, GitHub pre-fills the description box from .github/PULL_REQUEST_TEMPLATE.md. Below is a rendering of that file's new content — the existing four questions, plus the new 🧪 Sandbox section this PR adds.

Every key ships with an inline comment explaining it, and the values shown are exactly the sandbox's current defaults — so leaving the block untouched reproduces today's behavior (with the one exception noted in Overview: IS_SANDBOX=true now always rides along).

2. Editing the block and pushing

Nothing needs to be typed from scratch — an author edits one of the five values (say, flips whatsapp to true because they're testing a WhatsApp template) and either opens the PR or edits the description on an existing one. Full mechanics of what happens next — the gate check, the YAML→JSON parse, the redeploy — are in How an edit triggers a redeploy.

3. What comes back on the PR

Once the sandbox finishes deploying, the workflow posts (or updates) a comment on the PR with the live URLs, credentials, and — new as of this change — a settings: line summarizing the non-default values that were parsed out of the block. The rendering below reconstructs that comment shape from the workflow source (.github/workflows/sandbox.yml) and this branch's own live sandbox info, since this particular PR's description predates the template it's adding, so its own comment doesn't show the line.

That settings: two_regions=false whatsapp=false cron=true env_overrides=0 line only appears when at least one value differs from the defaults — see SETTINGS_SUMMARY in How an edit triggers a redeploy for exactly when it's shown.

What did not change

• The parser, the gate logic, and the deploy steps in

.github/workflows/sandbox.yml — all pre-existing, all untouched by this PR.

• The Dentolize application code — no packages/server, packages/prisma,

packages/clinic-web, or packages/clinic-mobile files are part of this diff.

• Any PR opened before this merged — like this PR itself, whose own

description was written before the template existed, so it doesn't carry the block (see Overview).