Add bio field and daily streak check-in for gamification

- User.Bio: a short (300 char) freeform profile bio, editable via
  PATCH /profile/bio, shown on discover cards and candidate detail (richer
  profiles beyond the fixed onboarding fields).
- User.StreakCount/LastActiveDate: POST /profile/checkin increments the
  streak on consecutive days, resets after a gap, no-ops if already
  checked in today. Backs a daily-return hook on the frontend.

internal/router/router.go

@@ -58,6 +58,9 @@ func Setup(
 		profile.POST("/photos", h.Profile.UploadPhoto)
 		profile.DELETE("/photos/:id", h.Profile.DeletePhoto)
 		profile.PATCH("/location", h.Profile.UpdateLocation)
+		profile.PATCH("/bio", h.Profile.UpdateBio)
+		// استریک روزانه (گیمیفیکیشن): هر بار اپ باز می‌شه یه بار صدا زده می‌شه
+		profile.POST("/checkin", h.Profile.CheckIn)
 	}
 
 	// -------- آنبوردینگ (نیاز به ورود) --------