chore: import upstream snapshot with attribution

.github/scripts/pr-review/pr-diff.sh

@@ -0,0 +1,128 @@
+#!/bin/bash
+# pr-diff.sh - Show changed files or diff for a specific file
+#
+# Usage: 
+#   pr-diff.sh           - List all changed files (shows full diff if small enough)
+#   pr-diff.sh <file>    - Show diff for a specific file with line numbers
+#
+# Environment variables (set by the composite action):
+#   PR_REVIEW_REPO       - Repository (owner/repo)
+#   PR_REVIEW_PR_NUMBER  - Pull request number
+
+set -e
+
+# Configuration from environment
+REPO="${PR_REVIEW_REPO:?PR_REVIEW_REPO environment variable is required}"
+PR_NUMBER="${PR_REVIEW_PR_NUMBER:?PR_REVIEW_PR_NUMBER environment variable is required}"
+EXPECTED_HEAD="${PR_REVIEW_HEAD_SHA:-}"
+
+# Check if HEAD has changed since review started (race condition detection)
+if [ -n "$EXPECTED_HEAD" ]; then
+  CURRENT_HEAD=$(gh api "repos/${REPO}/pulls/${PR_NUMBER}" --jq '.head.sha')
+  if [ "$CURRENT_HEAD" != "$EXPECTED_HEAD" ]; then
+    echo "⚠️  WARNING: PR head has changed since review started!"
+    echo "   Review started at: ${EXPECTED_HEAD:0:7}"
+    echo "   Current head:      ${CURRENT_HEAD:0:7}"
+    echo "   Line numbers below may not match the commit being reviewed."
+    echo ""
+  fi
+fi
+
+# Thresholds for "too big" - show file list only if exceeded
+MAX_FILES=25
+MAX_TOTAL_LINES=1500
+
+FILE="$1"
+
+# Function to add line numbers to a patch
+# Format: [LINE] +added | [LINE]  context | [----] -deleted
+add_line_numbers() {
+  awk '
+  BEGIN { new_line = 0 }
+  /^@@/ {
+    # Parse hunk header: @@ -old_start,old_count +new_start,new_count @@
+    match($0, /\+([0-9]+)/)
+    new_line = substr($0, RSTART+1, RLENGTH-1) - 1
+    print ""
+    print $0
+    next
+  }
+  /^-/ {
+    # Deleted line - cannot comment on these
+    printf "[----] %s\n", $0
+    next
+  }
+  /^\+/ {
+    # Added line - can comment, show line number
+    new_line++
+    printf "[%4d] %s\n", new_line, $0
+    next
+  }
+  {
+    # Context line (space prefix) - can comment, show line number
+    new_line++
+    printf "[%4d] %s\n", new_line, $0
+  }
+  '
+}
+
+if [ -z "$FILE" ]; then
+  # Get file list with stats
+  FILES_DATA=$(gh api "repos/${REPO}/pulls/${PR_NUMBER}/files" --paginate)
+  
+  FILE_COUNT=$(echo "$FILES_DATA" | jq 'length')
+  TOTAL_ADDITIONS=$(echo "$FILES_DATA" | jq '[.[].additions] | add // 0')
+  TOTAL_DELETIONS=$(echo "$FILES_DATA" | jq '[.[].deletions] | add // 0')
+  TOTAL_LINES=$((TOTAL_ADDITIONS + TOTAL_DELETIONS))
+  
+  echo "PR #${PR_NUMBER} Summary: ${FILE_COUNT} files changed (+${TOTAL_ADDITIONS}/-${TOTAL_DELETIONS})"
+  echo ""
+  
+  # Check if diff is too large
+  if [ "$FILE_COUNT" -gt "$MAX_FILES" ] || [ "$TOTAL_LINES" -gt "$MAX_TOTAL_LINES" ]; then
+    echo "⚠️  Large diff detected (>${MAX_FILES} files or >${MAX_TOTAL_LINES} lines changed)"
+    echo "   Review files individually using: pr-diff.sh <filename>"
+    echo ""
+    echo "Files changed:"
+    echo "$FILES_DATA" | jq -r '.[] | "  \(.filename) (+\(.additions)/-\(.deletions))"'
+  else
+    # Small enough - show all diffs with line numbers
+    echo "Files changed:"
+    echo "$FILES_DATA" | jq -r '.[] | "  \(.filename) (+\(.additions)/-\(.deletions))"'
+    echo ""
+    echo "─────────────────────────────────────────────────────────────────────"
+    echo ""
+    
+    # Show each file's diff by iterating over indices
+    for i in $(seq 0 $((FILE_COUNT - 1))); do
+      FNAME=$(echo "$FILES_DATA" | jq -r ".[$i].filename")
+      PATCH=$(echo "$FILES_DATA" | jq -r ".[$i].patch // empty")
+      
+      if [ -n "$PATCH" ]; then
+        echo "## ${FNAME}"
+        echo "Use: pr-comment.sh ${FNAME} <LINE> --severity <level> --title \"desc\" --why \"reason\" <<'EOF' ... EOF"
+        echo "Format: [LINE] +added | [LINE] context | [----] -deleted (can't comment)"
+        echo "$PATCH" | add_line_numbers
+        echo ""
+        echo "─────────────────────────────────────────────────────────────────────"
+        echo ""
+      fi
+    done
+  fi
+else
+  # Show specific file diff
+  PATCH=$(gh api "repos/${REPO}/pulls/${PR_NUMBER}/files" --paginate --jq --arg file "$FILE" '.[] | select(.filename==$file) | .patch')
+  
+  if [ -z "$PATCH" ]; then
+    echo "Error: File '${FILE}' not found in PR diff"
+    echo ""
+    echo "Files changed in this PR:"
+    gh api "repos/${REPO}/pulls/${PR_NUMBER}/files" --paginate --jq '.[].filename'
+    exit 1
+  fi
+  
+  echo "## ${FILE}"
+  echo "Use: pr-comment.sh ${FILE} <LINE> --severity <level> --title \"desc\" --why \"reason\" <<'EOF' ... EOF"
+  echo "Format: [LINE] +added | [LINE] context | [----] -deleted (can't comment)"
+  echo "$PATCH" | add_line_numbers
+fi