Preserve existing JSON formatting in automated submission PRs

[Copilot]

Issue-template submissions were rewriting the full target JSON file, especially normalizing frameworks arrays across all entries. That created formatting churn in every generated PR and turned unrelated follow-up submissions into merge conflicts.

• Workflow write path

  • Replaced full-file prettier.format(JSON.stringify(data)) output with source-preserving insertion logic in process-submission.yml.
  • The workflow now inserts only the new entry into the target top-level JSON array and leaves all untouched entries byte-for-byte unchanged.

• Minimal JSON patch behavior

  • Keeps the existing file layout, including prior per-entry array formatting, instead of reformatting the entire document.
  • Preserves alphabetical insertion by name, so generated PRs remain focused to the submitted record.

• Safety checks

  • Added validation around top-level array/object detection before writing.
  • Improved failure messaging when the target JSON structure is not the expected array-of-objects shape.

// Before
formattedData = await prettier.format(JSON.stringify(data), {filepath: filePath});
fs.writeFileSync(filePath, formattedData);

// After
const updatedSource = insertEntryIntoArraySource(source, entry, normalizedInsertIndex, data.length, targetFile);
fs.writeFileSync(filePath, updatedSource);