Add org-wide issue/PR intake bot workflow with deduped welcome comments and owner email alerts

[Copilot]

This PR adds a single organization-ready workflow (.github/workflows/org-bot.yml) that handles both new issues and new pull requests. On open, it posts a th30d4y-branded acknowledgement comment and sends an SMTP email notification with repository, type, title, and URL.

• Unified event handling

  • One workflow for issues.opened and pull_request.opened.
  • Normalizes event payload into shared metadata (type, number, title, url) for downstream steps.

• Comment automation (via actions/github-script)

  • Posts:

    👋 Hello! Thanks for your contribution. We will review this and get back to you as soon as possible. — th30d4y

  • Prevents duplicate bot comments by matching normalized comment body on the target thread.

• Owner notification email (Gmail SMTP)

  • Resolves organization admins and builds recipient list.
  • Sends formatted HTML email through smtp.gmail.com:465 using EMAIL_USER / EMAIL_PASS secrets.
  • Email includes repository, item type (Issue/Pull Request), title, and direct URL.

• Production hardening

  • Uses explicit job permissions (issues, pull-requests, members).
  • Handles unsupported payloads and API failures with explicit step failures.
  • Avoids shell-based interpolation of untrusted titles by deriving metadata in github-script.

on:
  issues:
    types: [opened]
  pull_request:
    types: [opened]