fix: Add missing label to Insights.kt - FileTypeGraphs

[MarioReina97]

What has changed

Added the missing "Native Files" label to FileTypeGraphs, ensuring that the corresponding file type is correctly represented in the Insights page.

Why was it changed

The missing label caused the Insights page to crash due to an undefined reference.
This change resolves errors such as:

Unexpected Application Error!
Cannot read properties of undefined (reading 'plus_u6jwas_k$')
TypeError: Cannot read properties of undefined (reading 'plus_u6jwas_k$')
    at ae (file:///.../ruler/sample/app/build/reports/ruler/release/report.html:25:2095642)

 Unexpected Application Error!
Cannot read properties of undefined (reading 'k')

How to test

1. Build a report with omitFileBreakdown.set(false).
2. Open the Ruler Insights page.
3. Verify that the "Native Files" section renders correctly and the page no longer crashes.

Related issues

#166