feat: module 05 assemble

Cards become JSON data in course/cards (one file per card, validated
against card.schema.json and the catalog); the M5 references load them
via registerCards and interpret effects, replacing content closures.
Adds assemble(base, donor, half), the assemble/buffHand effects with an
injected chooser, Fleshshape as the data-only Expansion Drop, and stages
course/cards in verify-references and start-module.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tools/test/verify-references.test.mjs

@@ -46,6 +46,17 @@ test("verify_stage_copies_all_earlier_module_tests", async () => {
   assert.ok(existsSync(join(dir, "Cargo.toml")));
 });
 
+test("verify_stage_copies_course_cards", async () => {
+  // From Module 5 the references load card data from <crate or package root>/cards.
+  process.env.COURSE_ROOT = root;
+  const { planVerification, stage } = await import("../verify-references.mjs");
+  const { existsSync } = await import("node:fs");
+  for (const lang of ["rust", "ts"]) {
+    const dir = stage(planVerification(moduleDirs(), 1)[0], lang);
+    assert.ok(existsSync(join(dir, "cards", "test-fixture.json")), lang);
+  }
+});
+
 test("verify_ts_default_installs_dependencies_first", async () => {
   // A staged reference has no node_modules; a bare `npx vitest` fetches the
   // latest vitest, which cannot load the reference's vitest.config.ts.