feat: integrate ProcessMetrics with child process tracking and fix tests

- Upgrade system-metrics to v1.2.0 with ProcessDelta support
- Enable child process tracking in JobProcessingListener (includeChildren: true)
- Fix CPU/memory metrics calculation in JobProcessedListener:
  - Use peak->memoryRssBytes instead of current (maximum RSS during execution)
  - Use delta->cpuUsagePercentage() instead of cumulative ticks
  - Proper CPU time calculation: (cpuPercent/100) * durationSeconds * 1000
- Add comprehensive test coverage:
  - 5 ProcessMetrics integration unit tests
  - 4 ChildProcessTracking feature tests with realistic scenarios
- Fix flaky performance benchmark tests with proper tolerances
- Merge conflict resolution: removed hooks system integration
- Update PHP requirement to ^8.3|^8.4 (system-metrics dependency requirement)

All tests passing: 125 tests, 350 assertions

Author: sylvesterdamgaard

.claude/settings.local.json

@@ -14,7 +14,23 @@
       "Bash(/Users/sylvester/Projects/Cbox/sandbox/artisan tinker:*)",
       "Bash(do)",
       "Bash(git rebase:*)",
-      "Bash(timeout 5 curl:*)"
+      "Bash(timeout 5 curl:*)",
+      "Bash(vendor/bin/pest:*)",
+      "Bash(vendor/bin/phpstan analyse:*)",
+      "mcp__serena__get_symbols_overview",
+      "mcp__serena__list_dir",
+      "Bash(find:*)",
+      "mcp__serena__find_file",
+      "mcp__serena__write_memory",
+      "mcp__serena__edit_memory",
+      "mcp__serena__read_memory",
+      "mcp__serena__find_symbol",
+      "mcp__serena__initial_instructions",
+      "mcp__serena__check_onboarding_performed",
+      "mcp__serena__get_current_config",
+      "mcp__serena__search_for_pattern",
+      "mcp__serena__think_about_collected_information",
+      "WebSearch"
     ],
     "deny": [],
     "ask": []

.gitignore

@@ -28,7 +28,6 @@ _ide_helper_models.php
 phpunit.xml
 phpstan.neon
 testbench.yaml
-/docs
 /coverage
 /.claude/
 /.serena/