Add explicit disclosure of excluded files in AI review prompt

Echo a note into the prompt listing any excluded data files so Codex
knows its diff is partial. Addresses P2: review should not appear to
have full coverage when large data files were omitted.

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

Author: igerber

.github/workflows/ai_pr_review.yml

@@ -147,10 +147,18 @@ jobs:
             echo "Changed files:"
             git --no-pager diff --name-status "$BASE_SHA" "$HEAD_SHA"
             echo ""
+            # Identify large data files excluded from the unified diff
+            EXCLUDED_GLOBS="benchmarks/data/real/*.json benchmarks/data/real/*.csv"
+            excluded_files=$(git --no-pager diff --name-only "$BASE_SHA" "$HEAD_SHA" -- $EXCLUDED_GLOBS)
+            if [ -n "$excluded_files" ]; then
+              echo "NOTE: The following files are excluded from the unified diff below"
+              echo "due to size (they are generated data/golden-value files). Their"
+              echo "filenames appear in the 'Changed files' list above, but their"
+              echo "content is NOT shown. Review coverage for these files is metadata-only."
+              echo "$excluded_files" | sed 's/^/  - /'
+              echo ""
+            fi
             echo "Unified diff (context=5):"
-            # Exclude large generated data files from the full diff to stay
-            # within the model's input limit. The --name-status above still
-            # lists them so the reviewer knows they changed.
             git --no-pager diff --unified=5 "$BASE_SHA" "$HEAD_SHA" \
               -- . ':!benchmarks/data/real/*.json' ':!benchmarks/data/real/*.csv'
           } >> "$PROMPT"