Add Russian translations for mineral property values

- Add properties_ru JSON field to store translated category, crystal_system,
  luster, streak, specific_gravity, color_description
- Add translate_minerals management command using deep-translator (Google
  Translate), with a hard-coded dictionary for crystal systems
- Template: show translated values in RU mode, fall back to English if missing
- Add deep-translator to requirements.txt

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

dailystone/models.py

@@ -19,6 +19,7 @@ class Mineral(models.Model):
     day_of_year = models.IntegerField(unique=True, null=True, blank=True)
 
     # Russian translations
+    properties_ru = models.JSONField(default=dict, blank=True)
     name_ru = models.CharField(max_length=200, blank=True)
     description_ru = models.TextField(blank=True)
     history_ru = models.TextField(blank=True)