fix: review round 3 — init @Finalized, vips driver, path existence check

- Initialize @Finalized = false explicitly in constructor
- Integration test uses driver: :vips for heatmap generation
- Assign @report_path before skip so teardown never gets nil
- relative_path checks file existence to avoid broken image links
  when annotation files don't exist (e.g. dimension mismatches)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: pftg

lib/capybara_screenshot_diff/reporters/html.rb

@@ -15,6 +15,7 @@ def initialize(output_path: "tmp/snap_diff-report/index.html")
         @report_dir = @output_path.dirname
         @failures = []
         @total = 0
+        @finalized = false
       end
 
       def record(assertions)
@@ -75,7 +76,10 @@ def failure_entry_for(name, compare)
       def relative_path(path)
         return unless path
 
-        Pathname.new(path).relative_path_from(@report_dir).to_s
+        pathname = Pathname.new(path)
+        return unless pathname.exist?
+
+        pathname.relative_path_from(@report_dir).to_s
       end
 
       def write_report

test/integration/report_screenshot_test.rb

@@ -7,14 +7,14 @@ class ReportScreenshotTest < SystemTestCase
   PERCEPTUAL_THRESHOLD = 2.0
 
   setup do
-    skip "Run with RECORD_SCREENSHOTS=1 to update report fixtures" unless ENV["RECORD_SCREENSHOTS"]
     @report_path = Pathname.new("test/fixtures/app/sample_report.html")
+    skip "Run with RECORD_SCREENSHOTS=1 to update report fixtures" unless ENV["RECORD_SCREENSHOTS"]
     generate_sample_report
     visit "/sample_report.html"
   end
 
   teardown do
-    FileUtils.rm_f(@report_path) if @report_path
+    FileUtils.rm_f(@report_path)
   end
 
   def test_report_both_view
@@ -58,7 +58,7 @@ def build_assertions
   end
 
   def build_assertion(name, base_path, new_path)
-    compare = Capybara::Screenshot::Diff::ImageCompare.new(new_path, base_path)
+    compare = Capybara::Screenshot::Diff::ImageCompare.new(new_path, base_path, driver: :vips)
     compare.processed
     CapybaraScreenshotDiff::ScreenshotAssertion.new(name).tap { |a| a.compare = compare }
   end