Implement auth, persistence, typed responses, and injectable RNG

Auth: JWT tokens (sb-auth) with argon2 password hashing, login/register
endpoints, Bearer token middleware protecting all routes except auth.
Authorization checks ensure users can only access their own characters.

Persistence: SQLite via rusqlite (sb-db) with write-through on all
mutations. Optional via SB_DB_PATH env var; falls back to in-memory.

Typed responses: ~20 response DTOs in sb-shared replacing ad-hoc JSON.

Combat: Injectable RNG via &mut impl Rng for deterministic tests.

Clean Architecture: Combat types and response DTOs in sb-shared; domain
services in sb-core; auth in sb-auth; persistence in sb-db.

crates/sb-core/src/items.rs

@@ -1,13 +1,34 @@
-pub mod mod;
+use sb_shared::Item;
 
-use sb_common::PROJECT_NAME;
+const WEAPONS_JSON: &str =
+    include_str!("../../../../skara-brae-common/data/items/weapons.json");
+const ARMOR_JSON: &str =
+    include_str!("../../../../skara-brae-common/data/items/armor.json");
+const ACCESSORIES_JSON: &str =
+    include_str!("../../../../skara-brae-common/data/items/accessories.json");
 
-const WEAPONS: &str = include_str!("../../../../skara-brae-common/data/items/weapons.json");
+pub fn load_all_items() -> Vec<Item> {
+    let mut items = Vec::new();
 
-pub fn game_name() -> &'static str {
-    PROJECT_NAME
+    let weapons: Vec<Item> =
+        serde_json::from_str(WEAPONS_JSON).expect("failed to parse weapons.json");
+    items.extend(weapons);
+
+    let armor: Vec<Item> =
+        serde_json::from_str(ARMOR_JSON).expect("failed to parse armor.json");
+    items.extend(armor);
+
+    let accessories: Vec<Item> =
+        serde_json::from_str(ACCESSORIES_JSON).expect("failed to parse accessories.json");
+    items.extend(accessories);
+
+    items
 }
 
-pub fn load_weapons() -> Vec<serde_json::Value> {
-    serde_json::from_str(WEAPONS).expect("failed to parse weapons data")
+pub fn item_price(item: &Item) -> i32 {
+    item.value
+}
+
+pub fn item_sell_price(item: &Item) -> i32 {
+    item.value / 2
 }