Fix code highlighting and optimize category select

This commit introduces a batched debounce mechanism for managing user
selection state changes. It effectively reduces unnecessary processing
during rapid script checking, preventing multiple triggers for code
compilation and UI rendering.

Key improvements include:

- Enhanced performance, especially noticeable when selecting large
  categories. This update resolves minor UI freezes experienced when
  selecting categories with numerous scripts.
- Correction of a bug where the code area only highlighted the last
  selected script when multiple scripts were chosen.

Other changes include:

- Timing functions:
  - Create a `Timing` folder for `throttle` and the new
    `batchedDebounce` functions.
  - Move these functions to the application layer from the presentation
    layer, reflecting their application-wide use.
  - Refactor existing code for improved clarity, naming consistency, and
    adherence to new naming conventions.
  - Add missing unit tests.
- `UserSelection`:
  - State modifications in `UserSelection` now utilize a singular object
    inspired by the CQRS pattern, enabling batch updates and flexible
    change configurations, thereby simplifying change management.
- Remove the `I` prefix from related interfaces to align with new coding
  standards.
- Refactor related code for better testability in isolation with
  dependency injection.
- Repository:
  - Move repository abstractions to the application layer.
  - Improve repository abstraction to combine `ReadonlyRepository` and
    `MutableRepository` interfaces.
- E2E testing:
  - Introduce E2E tests to validate the correct batch selection
    behavior.
  - Add a specialized data attribute in `TheCodeArea.vue` for improved
    testability.
  - Reorganize shared Cypress functions for a more idiomatic Cypress
    approach.
  - Improve test documentation with related information.
- `SelectedScript`:
  - Create an abstraction for simplified testability.
  - Introduce `SelectedScriptStub` in tests as a substitute for the
    actual object.

docs/tests.md

@@ -81,8 +81,10 @@ These checks validate various qualities like runtime execution, building process
     - [`Stubs/`](./../tests/unit/shared/Stubs): Maintains stubs for component isolation, equipped with basic functionalities and, when necessary, spying or mocking capabilities.
 - [`./tests/integration/`](./../tests/integration/): Contains integration test files.
 - [`cypress.config.ts`](./../cypress.config.ts): Cypress (E2E tests) configuration file.
+- [`cypress-dirs.json`](./../cypress-dirs.json): A central definition of directories used by Cypress, designed for reuse across different configurations.
 - [`./tests/e2e/`](./../tests/e2e/): Base Cypress folder, includes tests with `.cy.ts` extension.
-  - [`/support/e2e.ts`](./../tests/e2e/support/e2e.ts): Support file, runs before every single spec file.
   - [`/tsconfig.json`]: TypeScript configuration for file Cypress code, improves IDE support, recommended to have by official documentation.
   - *(git ignored)* `/videos`: Asset folder for videos taken during tests.
   - *(git ignored)* `/screenshots`: Asset folder for Screenshots taken during tests.
+  - [`/support/e2e.ts`](./../tests/e2e/support/e2e.ts): Support file, runs before every single test file.
+  - [`/support/interactions/`](./../tests/e2e/support/interactions/): Contains reusable functions for simulating user interactions, enhancing test readability and maintainability.