fifa17 store: real 6-pack economy + full-DB pool; drop extPrice

- store_catalog: replace the invented catalogue with the real always-available
  FUT17 regular packs (Bronze/Prem Bronze/Silver/Prem Silver/Gold/Prem Gold) at
  real prices + tier composition; PackDef now carries per-tier quantities.
- pack_body: drop extPrice (its mtx side-effect switched on the broken "or %1s"
  FIFA-Points tile line; plan-2026-08-05-store-subsystem.md section 3.4).
- pack_content: tier-aware generator draws each pack bronze/silver/gold
  composition with special_chance bias + empty-tier fallback.
- host: CoreAccess::all_definitions (GET /cards); build_content_pool draws the
  FULL card universe via non-minting catalog lookup, owned-inventory fallback.
- economy_differential: store ops reclassified DIFFERENT-BY-DESIGN (Rust is the
  authoritative store; Python oracle stays the untouched rollback baseline).
- fixtures/tests updated to the real catalogue.

Odds are DESIGNED placeholders (FUT17 pack probabilities were never published);
club items remain excluded (cardtype-9 mapping unknown). Full regression green;
real prices + tier-correct draws verified server-side on staging.

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"