fix: preserve local env overrides in shell pipelines

scripts/load_project_env.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+PATH_ARG="${1:-}"
+[[ -n "$PATH_ARG" && -f "$PATH_ARG" ]] || exit 0
+
+python3 - <<'PY' "$PATH_ARG"
+from pathlib import Path
+import sys
+
+for raw in Path(sys.argv[1]).read_text().splitlines():
+    s = raw.strip()
+    if not s or s.startswith('#') or '=' not in s:
+        continue
+    key, value = s.split('=', 1)
+    key = key.strip()
+    value = value.strip().strip('"').strip("'")
+    if not key or not value:
+        continue
+    print(f"{key}={value}")
+PY