feat: user profile customization: username, password, and avatar (#315)

frontend/messages/en.json

@@ -77,6 +77,7 @@
     "projects": "Projects",
     "admin": "Administration",
     "account": "Account",
+    "profile_settings": "Profile Settings",
     "signup": "Sign up",
     "signin": "Sign in",
     "signout": "Sign out",
@@ -112,7 +113,27 @@
     "public": "Public",
     "private": "Private",
     "not_own_any_projects": "You don't own any projects.",
-    "find_projects": "Find projects"
+    "find_projects": "Find projects",
+    "profile_settings": "Profile Settings",
+    "change_username": "Change Username",
+    "new_username": "New Username",
+    "update_username": "Update Username",
+    "username_updated": "Username updated successfully",
+    "change_password": "Change Password",
+    "current_password": "Current Password",
+    "new_password": "New Password",
+    "confirm_new_password": "Confirm New Password",
+    "update_password": "Update Password",
+    "password_updated": "Password updated successfully",
+    "change_avatar": "Change Avatar",
+    "upload_avatar": "Upload Avatar",
+    "remove_avatar": "Remove Avatar",
+    "avatar_updated": "Avatar updated successfully",
+    "avatar_removed": "Avatar removed successfully",
+    "max_file_size_5mb": "Max. file size: 5MB",
+    "only_images_allowed": "Only image files are allowed",
+    "current_password_incorrect": "Current password is incorrect",
+    "update_error": "Update failed"
   },
   "Health": {
     "health_check": "Health Check",