Summary

This PR adds performance profiling infrastructure for hint filtering and fixes bugs in the existing perf commands.

Changes

1. Perf markers in hint filtering (src/content/hinting.ts)

Added Perf.Marker instrumentation to filterHintsSimple and filterHintsVimperator functions to measure hint filtering performance:

• filterHintsSimple - measures simple prefix-based hint filtering
• filterHintsVimperator - measures vimperator-style hint filtering with text matching

These markers allow benchmarking hint filtering performance before/after optimizations.

2. Fixed perfdump/perfhistogram commands (src/excmds.ts)

The original implementation used open("data:...") to display results, which is blocked by Firefox for extensions due to security restrictions. Changed to:

• Output to browser console for easy viewing
• Copy results to clipboard for pasting elsewhere
• Show a message in the command line with result summary

3. Fixed StatsFilter.matches() (src/perf.ts)

Fixed a bug where StatsFilter.matches() would crash when processing performance entries that don't match the expected tri/Owner/Function:suffix naming pattern. Added null check to handle entries that can't be parsed.

Usage

To profile hint filtering performance:

:set perfcounters true
# Use hint filtering (press f and type to filter)
:perfhistogram Hinting/

This enables measuring and comparing hint filtering performance on pages with many links (e.g., GitHub file listings).