feat: add candidate FreeCAD naming SDK and attachment oracles

Build and verify the candidate-only FreeCAD naming bridge and OCCT worker path, including three-stage StringHasher restoration. Add Datum, ShapeBinder, attachment-mode, and PartDesign structure oracles plus offline SDK build plans and CI boundary checks.

scripts/boost-emscripten-compiler-wrapper.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [[ "${1:-}" == "-r" && "${2:-}" == "-o" && -n "${3:-}" ]]; then
+  output="$3"
+  shift 3
+  exec emar rcs "${output}" "$@"
+fi
+
+exec emcc "$@"