chore: wp.org submission prep — v0.1.3

Rebrand to RangerHQ Buddy and prepare for the WordPress.org Plugin
Directory. Same workflow as rangerhq-radio v0.7.0 → v0.7.5.

Changes:
- Plugin Name: Buddy → RangerHQ Buddy (matches family naming)
- Plugin URI: icanhelp.ie/buddy → davidtkeane.com/rangerhq-buddy
- Author URI: rangersmyth.xyz → davidtkeane.com
- Text Domain: buddy → rangerhq-buddy (62 occurrences across 8 PHP files)
- Add LICENSE file (full GPL v2 text from gnu.org)
- Add wp.org-format readme.txt with all 8 required headers
- Remove inc/updater.php (self-hosted Gitea updater forbidden for
  wp.org-hosted plugins per the rangerhq-radio v0.7.3 walkback)
- Replace mt_rand with wp_rand in inc/state.php for better RNG
- Add 5 translator comments for printf-style i18n placeholders
- Wrap 2 dashboard-widget.php printf placeholders in (int) casts
- Add tests/ to .gitignore (PCP reports are local-only)

PCP audit: 85 issues → ~1 (the .gitignore file itself, stripped from
the submission zip).
Plugin Check Namer Tool: "Generally Allowable" verdict on both name
and slug.
Plugin URI https://davidtkeane.com/rangerhq-buddy/ returns HTTP 200.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitignore

@@ -12,3 +12,4 @@ composer.lock
 
 # Build artifacts
 *.zip
+tests/