path-based deterministic tagging

.github/workflows/build.yml

@@ -72,7 +72,8 @@ jobs:
           # If workflow changed, rebuild all lanes (use basenames)
           if grep -qx ".github/workflows/build.yml" <<< "$CHANGED"; then
             echo "Workflow changed; rebuilding all lanes."
-            TARGET_DIRS=("${ALL_NAMES[@]}")
+            # Use full lane paths (e.g. 'docker/7.4') so downstream steps get deterministic dirs
+            TARGET_DIRS=("${ALL_LANES[@]}")
           else
             # Build only lanes with changes under their directories
             TARGET_DIRS=()
@@ -81,7 +82,8 @@ jobs:
               lane_name="${ALL_NAMES[$idx]}"
               # Any change directly under lane dir counts; include Dockerfile or subpaths
               if grep -q "^${lane_path}/" <<< "$CHANGED"; then
-                TARGET_DIRS+=("${lane_name}")
+                # Append the full lane path (e.g. 'docker/7.4')
+                TARGET_DIRS+=("${lane_path}")
               fi
             done
           fi