feat: fully implement profile controller;

feat: implement file upload handling in controller with size and type validation;
feat: add custom validation rules for bio and color hex fields;
refactor: enhance request handling with dedicated client info extraction;
chore: update profile DTOs with validation tags;
docs: profile controller swagger

backend/internal/validation/custom.go

@@ -48,6 +48,20 @@ func GetCustomHandlers() []CustomValidatorHandler {
         return regexp.MustCompile(`^.{1,75}$`).MatchString(username)
 		}},
 
+		{
+			FieldName: "bio",
+			Function: func(fl validator.FieldLevel) bool {
+				username := fl.Field().String()
+        return regexp.MustCompile(`^.{1,512}$`).MatchString(username)
+		}},
+
+		{
+			FieldName: "color_hex",
+			Function: func(fl validator.FieldLevel) bool {
+				username := fl.Field().String()
+        return regexp.MustCompile(`^#[0-9a-f]{6,6}$`).MatchString(username)
+		}},
+
 		{
 			FieldName: "password",
 			Function: func(fl validator.FieldLevel) bool {