wip(fifa17): pre-existing SBC/economy candidate snapshot

Snapshot of the uncommitted economy/SBC candidate work that built the tested
sbc-host on top of e8d1c1d (NOT authored in this session; committed to leave a
clean tree). Covers pack_content, sbc, store_catalog, host economy_store/lib,
purchasegroup fixtures, economy integration/concurrency/differential tests,
and Cargo.lock. Content matches the running staging host binary.

openfut-utas-host/tests/economy_integration.rs

@@ -373,8 +373,8 @@ fn economy_sequence(base: &str, dir: &std::path::Path) -> SeqResult {
         .as_array()
         .expect("itemList")
         .clone();
-    assert_eq!(items.len(), 5, "pack 1 awards 5 cards");
-    assert_eq!(bv["createPackResponse"]["numberItems"], 5);
+    assert_eq!(items.len(), 12, "pack 1 (real Bronze Pack) awards 12 cards");
+    assert_eq!(bv["createPackResponse"]["numberItems"], 12);
     assert!(
         items[0]["id"].as_i64().unwrap() >= 100_000_000,
         "minted wire id above the FIFA floor"