Fix KiCad WASM startup issues

- Increase thread pool size from 4 to 8 with STRICT=0 to prevent
  "thread pool exhausted" errors when KiCad creates worker threads
- Add thisProgram='/usr/bin/pcbnew' to provide absolute path for
  argv[0], fixing "No meaningful argv[0]" DEBUG check in KiCad

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/wasm-app/kicad/pcbnew.html

@@ -106,6 +106,7 @@
     };
 
     var Module = {
+      thisProgram: '/usr/bin/pcbnew',  // Fake absolute path for argv[0] (KiCad DEBUG check)
       preRun: [createCanvas],
       postRun: [],