Add generic type parameters for optional strong typing of Options and Cell component for template type checking

[johanrd]

Summary

• Adds generic type parameters (OptionsType and CellArgs) throughout the table system for improved type safety
• Enables strongly-typed Cell component arguments for better Glint/TypeScript inference
• Splits CellContext into two types: CellConfigContext (for configuration) and CellContext (for runtime)
• Exports CellContext as part of the public API

Motivation

When defining custom Cell components with custom options, there was no way to get proper type safety in Glint. This change allows developers to specify the exact shape of their Cell component arguments and options, enabling full type inference in templates.

Changes

• Table, Column, TableConfig, ColumnConfig, and headlessTable now accept OptionsType and CellArgs generic parameters
• CellContext split into:
  • CellConfigContext<T, OptionsType>: For defining column options (optional fields for user convenience)
  • CellContext<T, OptionsType>: For Cell components (required fields since they're always provided at runtime)
• CellContext exported from the public API for easier type annotations

Example Usage

interface MyOptions {
  customField: string;
  anotherField: number;
}

interface MyCellArgs {
  data: MyDataType;
  column: Column<MyDataType, MyOptions>;
  options: MyOptions;
}

const table = headlessTable<MyDataType, MyOptions, MyCellArgs>(this, {
  columns: () => [{
    key: 'custom',
    Cell: MyCustomCell, // now fully typed!
    options: ({ row }) => ({
      customField: row.data.value,
      anotherField: 42
    })
  }],
  data: () => myData
});

Breaking Changes

None - the new generic parameters default to any, maintaining backward compatibility.

[NullVoxPopuli]

If you do knownown, are things able to be inferred (maybe not so explicitly needed?)

[johanrd]

yes, important question. I see the tests are failing. Will look into it (works on my machine™)

[NullVoxPopuli]

T previously allowed for inferred types - does this still work?