[paulyhedral]

Summary

• Embed shared-web's feedback widget (CSS + JS from SHARED_URL) into main-web's landing page nav
• Add a "Report a problem / request a feature" nav button (btn btn-ghost) as the widget's custom trigger, localized via tr.menu_feedback()
• Add FEEDBACK_API_URL config (default dev admin-api public ingress URL) rendered into the widget's data-api-url attribute
• Related: added ALLOWED_ORIGINS CORS config for dev.sweetrpg.com to admin-api's dev configmap (feat(feedback): anonymous feedback submission via GitHub Issues proxy admin-api#95) - this is the first browser-side cross-origin caller of admin-api, every prior consumer fetched server-side

Part of sweetrpg/platform#112 (tasks.md group 4).

Test plan

• cargo fmt --check, cargo clippy --all-targets, cargo test all pass
• scripts/check-template-strings.sh passes (no literal untranslated strings)
• Manual dev-environment check: widget renders, trigger opens modal, submission reaches admin-api cross-origin without a CORS error