feat: professional repo cleanup + community infrastructure

- README: remove Recent Updates section, clean roadmap (pending only),
  replace Screenshots with demo link, add 6 new badges (stars, last
  commit, contributors, discussions, CI), invite GIF contributions
- CHANGELOG: translate all Italian entries to English, add v1.7.13
  (DB fresh-install crash fix)
- database.php: add missing 'undone' column to transactions schema;
  wrap ALTER TABLE calls in try/catch to prevent race-condition errors
  on concurrent first requests
- Wiki: Android-Kiosk v1.5.0 → v1.6.0, Step 5 rewritten (BLE scan,
  no external APK), removed gateway troubleshooting section
- Wiki: Scale-Gateway promoted to deprecated with redirect banner
- Wiki: Home What's New updated to v1.7.12 / v1.7.13
- Wiki: Features.md, kiosk README Italian UI strings translated
- .github: add bug_report.yml, feature_request.yml issue templates,
  config.yml (blank issues off, links to FAQ/Discussions/Security),
  PULL_REQUEST_TEMPLATE.md with checklist
- .github: FUNDING.yml (Ko-fi), dependabot.yml (monthly action updates)
- .github/workflows/security.yml: Trivy docker + fs scan, SARIF upload
- .github/workflows/build-scale-gateway.yml: disabled (deprecated)
- SECURITY.md: responsible disclosure policy, supported versions, scope
- CODE_OF_CONDUCT.md: Contributor Covenant 2.1
- Settings UI: About section with version display, Report Bug button,
  Changelog and GitHub links; reportBugManual() + _loadAboutSection()
- Translations: added 'about' key group (9 keys × 3 languages)

.github/FUNDING.yml

@@ -0,0 +1 @@
+ko_fi: dadaloop82