HTML feature report is very slow to open and uses excessive memory for large feature (177 scenarios, ~42 MB)

Description

Karate HTML reports work well for the summary page and for feature reports with a small number of scenarios. However, opening the HTML report for a feature with many scenarios is extremely slow and consumes a large amount of browser memory.

Environment

Item	Value
Karate version	2.0.10
Java version	21
OS	Ubuntu 24.04.4 LTS
Browser	Chrome Version 149.0.7827.155 (Official Build) (64-bit)
Report type	HTML (default)

Affected feature

• Number of scenarios: 177
• Generated HTML report file size of the specific feature: ~42 MB
• Time to open/render in browser: ~1 min 40 sec
• Browser memory usage while loading: ~6 GB
• The report is served over HTTP

Expected behavior

The feature HTML report should load in a reasonable time without consuming several GB of RAM.

Actual behavior

• The feature report page takes ~100 seconds to become usable.
• Chrome uses ~6 GB of memory during/after loading.
• Smaller feature reports and the summary page work fine.

Additional context

• Tried to open it locally via file://, similar behavior
• Tested in Edge, same behavior