Black Inset Border of Canvas Obstructing Display of Pixels

This is happening in older v1 as well as the latest v2.1.0 versions of jsnes, regardless of whether manually I set the canvas image data from the frameBuffer or let the new `Browser` class handle it.

- The canvas is set to 256×240.
- Other than `display: block`, no CSS is applied that would add borders, render outline, or cause collisions with canvas rendering

The most noticeable instance is the Tecmo Super Bowl Team Control screen in which the team's names and selection SKP/MAN/COA/COM values are cut off.

Start by reproducing the issue with a 256×240 canvas, then inspect the Browser class canvas-rendering path and the manual frameBuffer image-data path. Compare the rendered canvas bounds with the expected 256×240 display and verify that Tecmo Super Bowl text and selection values are no longer clipped.

Written by the indexing model from the issue text.