feat(db): 升级资产表新增 name，并补全 CRUD 核心逻辑

src/db/schema.ts

@@ -18,6 +18,7 @@ export const assetTypeEnum = pgEnum("asset_type_enum", [
 export const assets = pgTable("assets", {
   id: uuid("id").primaryKey().$defaultFn(() => crypto.randomUUID()),
   symbol: varchar("symbol", { length: 20 }).notNull().unique(),
+  name: varchar("name", { length: 100 }),
   type: assetTypeEnum("type").notNull(),
   exchange: varchar("exchange", { length: 10 }).default('US'),
   baseCurrency: varchar("base_currency", { length: 10 }).notNull(),