add agents instruction & remove old comment

# Agent Instructions

## Language

- Write all code and comments in English

## Naming conventions

- `my-class` — CSS classes use kebab-case

- `camelCase` — variables

- `$variableName` — DOM Node variables are prefixed with `$`

- `MAJUSCULE` — global constants use UPPERCASE

## File conventions

- `object.manager.js` — directive class coordinating sub-classes or views

- `object.class.js` — single-responsibility class used by a manager

## Function & JSDoc conventions

- Add a blank line between each function

- Any function created by an agent must include a JSDoc block with:

  - A function description

  - Parameters with their types

  - Return value with its type

- Use JSDoc for all functions with this format:

  - `/** Description. */`

  - `@param {Type} paramName Description.`

  - `@returns {Type} Description.`

- For functions returning nothing, use `@returns {void}`

- For optional parameters, use `@param {Type} [paramName] Description.`

## Async conventions

- Do not leave floating promises

- Prefer `async/await` over chained `.then()` calls

## Import conventions

- Group imports in this order:

  - External dependencies

  - Internal modules

  - Styles and assets

- Keep imports sorted within each group

## UI text conventions

- Do not hardcode user-facing strings in views

- Use translation keys and language files in `app/public/assets/languages/*.json`

## Validation conventions

Run the formatter from the `app/` directory before finishing:

- After code changes, run:

  - `cd app && npm run format`

  - `cd app && npm run check`

## Canary test

- If the user writes "canary", answer exactly: "AGENTS_OK"

 No newline at end of file

    const $total = document.getElementById("total-step");

    $total.innerText = total;

  }

  // BUTTON EVENTS

  /**

   * Executes a user step and manages the visual state of its button.

   */

  onStepFailed() {}

  // /BUTTON EVENTS

  /**

   * Updates the download progress in the UI.

   *