fix(ci): use portable LOC formatting in stats workflow

.gitea/workflows/update-readme.yaml

@@ -27,8 +27,12 @@ jobs:
           DEBIAN_FRONTEND: noninteractive
         run: |
           set -eu
+
+          if ! command -v jq >/dev/null 2>&1 ||
+             ! command -v python3 >/dev/null 2>&1; then
             apt-get update
             apt-get install -y --no-install-recommends jq python3
+          fi
 
       - name: Process Statistics and Update README
         run: |
@@ -39,9 +43,12 @@ jobs:
           echo "Global Commit Velocity: $TOTAL_COMMITS"
           echo "COMMIT_VELOCITY=$TOTAL_COMMITS" >> $GITHUB_ENV
 
-          LOC=$(grep '"total_code"' public/code-stats.json | sed 's/[^0-9]*//g')
-          FORMATTED_LOC=$(printf "%'d" $LOC)
-          echo "FORMATTED_LOC=$FORMATTED_LOC" >> $GITHUB_ENV
+          LOC=$(jq -er '.total_code' public/code-stats.json)
+
+          FORMATTED_LOC=$(python3 -c \
+            'import sys; print(f"{int(sys.argv[1]):,}")' "$LOC")
+
+          echo "FORMATTED_LOC=$FORMATTED_LOC" >> "$GITHUB_ENV"
 
           python3 scripts/generate_heatmap_svg.py public/heatmap.json public/heatmap.svg