MonthViewRenderer._renderEvent doesn't use getContrastingTextColor

[thedhanawada]

Bug Description

`MonthViewRenderer._renderEvent()` (lines 103-111 in `src/renderers/MonthViewRenderer.js`) hardcodes `color: white` for event text:

```js
_renderEvent(event) {
const color = this.getEventColor(event);
return `

${this.escapeHTML(event.title)}

`;
}
```

Meanwhile, `BaseViewRenderer.renderTimedEvent()` correctly calls `this.getContrastingTextColor(color)` to compute readable text color.

Impact

• Events with light background colors (e.g., yellow, light green, white) have white-on-light text — unreadable
• Inconsistent behavior between month view events and week/day view events
• Accessibility issue: fails WCAG contrast ratio requirements for light event colors

Expected Fix

Use `this.getContrastingTextColor(color)` instead of hardcoded `white`:
```js
const textColor = this.getContrastingTextColor(color);
// ... style="... color: ${textColor}; ..."
```

Files

• `src/renderers/MonthViewRenderer.js:103-111`
• Compare with `src/renderers/BaseViewRenderer.js:249` (correct usage)