feat: cell activation info

[BrianHung]

This is useful if internal editor state depends on how the cell is activated. For example, "enter" key has different behavior from "F2" in Excel.

[Copilot]

Pull Request Overview

This PR adds cell activation information to provide context about how a cell was activated (e.g., via keyboard "Enter" vs "F2", or via single-click vs double-click). This enables internal editor state to behave differently based on the activation method, similar to Excel's behavior.

• Introduces new CellActivatedEventArgs types to capture activation context
• Updates the onCellActivated callback to include activation information as a second parameter
• Passes activation details through to custom editor providers

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
packages/core/src/internal/data-grid/event-args.ts	Defines new activation event types with keyboard and pointer variants
packages/core/src/internal/data-grid/data-grid-types.ts	Updates editor provider types to include activation information
packages/core/src/data-editor/data-editor.tsx	Implements activation event creation and propagation throughout the component
packages/core/src/internal/data-grid-overlay-editor/data-grid-overlay-editor.tsx	Passes activation context to custom editors
packages/core/src/index.ts	Exports new activation event types
packages/core/test/data-editor.test.tsx	Updates tests to verify activation information is properly passed
packages/core/API.md	Documents the new activation event parameter