fix: prevent duplicate body template when PR body is modified

[SetupCoding]

Summary

Fixes duplicate body template insertion when the PR body has been manually edited by a user.

Problem

The current duplicate detection uses startsWith() / endsWith() to check if the template is already present in the PR body. This only works if the template remains at the exact start or end of the body.

When a user edits the PR body — adding text before a prefixed template or after a suffixed template — the positional check fails and the action inserts the template again, creating duplicates on every subsequent trigger.

Example scenario (prefix mode):

1. Action runs → prepends template to body ✅
2. User edits PR body, adds text above the template
3. Action re-runs → startsWith() check fails → template prepended again ❌ (duplicate)

Fix

Replace startsWith() / endsWith() with includes() so the duplicate check finds the template regardless of its position within the body.

  const updateBody = ({
-   prefix: !body.toLowerCase().startsWith(inputs.bodyTemplate.toLowerCase()),
-   suffix: !body.toLowerCase().endsWith(inputs.bodyTemplate.toLowerCase())
+   prefix: !body.toLowerCase().includes(inputs.bodyTemplate.toLowerCase()),
+   suffix: !body.toLowerCase().includes(inputs.bodyTemplate.toLowerCase())
  })[inputs.bodyUpdateAction] || false;

Additional changes

• Updated action.yml runtime from node16 to node24 (Node.js 20 deprecation on June 2nd 2026)
• Rebuilt dist/index.js with @vercel/ncc