Summary

Adds the ability for extension authors to specify a custom help URL for their actions, conditions, and expressions. When a URL is provided, a help icon (question mark) appears next to the instruction title, allowing users to quickly access external documentation.

Changes

Core (C++)

• Added helpUrl field to EventsFunction with getter/setter methods
• Updated serialization to persist helpUrl in project files

GDevelop.js Bindings

• Exposed getHelpUrl() and setHelpUrl() methods to JavaScript

Metadata Generation

• Updated MetadataDeclarationHelper to propagate helpUrl to InstructionMetadata and ExpressionMetadata

Editor UI

• Added "Help page URL" input field in the extension function properties editor
• Added help icon next to action/condition titles when custom URL is set
• Added help icon next to expressions in the expression selector
• Preserved existing "Help for this action/condition" button for wiki-based help

Utils

• Added isDocumentationAbsoluteUrl() and isRelativePathToDocumentationRoot() helpers to distinguish between custom URLs and wiki paths

Tests

• C++ unit tests for EventsFunction helpUrl serialization
• GDevelop.js binding tests for EventsFunction and MetadataDeclarationHelper
• React tests for HelpLink utility functions
• Updated Storybook for HelpIcon component

Screenshots