feat(routines): add minoxidil beard/mustache option to routine suggestions

- Add include_minoxidil_beard flag to SuggestRoutineRequest and SuggestBatchRequest
- Detect minoxidil products by scanning name, brand, INCI and actives; pass them
  to the LLM even though they are medications
- Inject CELE UŻYTKOWNIKA context block into prompts when flag is enabled
- Add _build_objectives_context() returning empty string when flag is off
- Add call_gemini() helper that centralises Gemini API calls and logs every
  request/response to a new ai_call_logs table (AICallLog model + /ai-logs router)
- Nginx: raise client_max_body_size to 16 MB for photo uploads

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nginx/innercontext.conf

@@ -4,6 +4,7 @@ server {
 
     # FastAPI backend — strip /api/ prefix
     location /api/ {
+        client_max_body_size 16m;  # up to 3 × 5 MB photos
         proxy_pass         http://127.0.0.1:8000/;
         proxy_set_header   Host              $host;
         proxy_set_header   X-Real-IP         $remote_addr;