chore(audit): drop unused ignore_paths method

Refactoring `ignored?` to inline both implicit and user ignore logic
left `ignore_paths` orphaned — nothing in the gem or tests calls it.
Per Copilot review on PR #4. Removing it (rather than wiring it back)
to keep the actual filter behavior in one place; if a future use
needs the combined list, reach for `IMPLICIT_IGNORE + Array(@config[
"ignore"])` directly.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jathayde

lib/guardrails/audit.rb

@@ -90,12 +90,6 @@ def scan_paths
       Array(paths)
     end
 
-    def ignore_paths
-      # Returned for the audit config knob; the actual filter logic lives
-      # in `ignored?` because implicit and user ignores match differently.
-      IMPLICIT_IGNORE + Array(@config["ignore"] || [])
-    end
-
     def collect_files
       patterns = scan_paths.map { |p| File.join(p, "**/*.html.erb") }
       patterns