Add Help contact form and PHP mail endpoint for support@katerion.ru, with validated Reply-To, explicit diagnostics consent, CSRF/origin checks, hashed rate limits and duplicate protection. Preserve drafts on error and avoid serializing customer data or SDK internals. Full PR QA passed in 35559317001; isolated PHP and 30 browser cases passed in 35559179372. Standard production gates unchanged. Publication checks do not send real mail; inbox receipt remains unverified. No training photo assets or unfinished training lifecycle changes.
The Поддержка tab opens an assistant that answers how-to questions from
the handbook. The chat is a sandboxed iframe on the assistant's own
origin and is only loaded after an explicit click, so Help and its search
stay local and no third-party script runs inside the app.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
