Initial commit: @b2c/first_page HarmonyOS stage-mode HAR

## Repository
- HarmonyOS stage-mode HAR module, consumed by host app
- No standalone build — hvigorw, oh_modules, and ../biz_quote absent here

## Architecture
### Feed Cards
- FirstPage.createNodeView dispatches cards by FirstPageConstant.KEY_*
- Card config from first_page_cards_config.json loaded by FirstPageCardsConfigLoader
- Public entrypoint: Index.ets

### Market Ranking (src/main/ets/market-ranking/)
- HTTP: MarketRankingDataFetcher fetches recommend_futures contracts
- HQ: MarketRankingHqRequestClient subscribes via 4106/frame 2201/scenario qht_qihuo_sort
- TCP reconnect rebuilds subscription from original HTTP contract list
- Async callbacks guarded by request/subscription versions

### Other Cards
- HotList, CommodityOptions, AiDiagnosis, AiRiseFall, SelfSelectedStock, CustomEntryList, FourEntryList
- Each has DataFetcher + HQ request client + NodeComponent

## Key Changes (from CardHarmonyOS reference)
- Added MetricId, PeriodId, SortOrder enums (MarketRankingModels.ets)
- Replaced string comparisons with enum switches in thirdColumnTitle/Value/Color
- Removed redundant undefined guards in thirdColumnColor/priceColor, delegated to riseFallColor
- Inlined priceColor(), use riseFallColor directly
- Tab bar Stack.height(30), Alignment.End (reverted from 46/TopEnd)
- Name column fontWeight removed (default regular)

src/main/ets/market-ranking/MarketRankingModels.ets

@@ -0,0 +1,73 @@
+export enum MetricId {
+  RISE = 'rise',
+  FALL = 'fall',
+  RISE_SPEED = 'riseSpeed',
+  FALL_SPEED = 'fallSpeed',
+  TURN_OVER = 'turnOver',
+  INCRE_POSIT = 'increPosit',
+}
+
+export enum PeriodId {
+  ONE_MIN = '1min',
+  FIVE_MIN = '5min',
+  TEN_MIN = '10min',
+  FIFTEEN_MIN = '15min',
+}
+
+export enum SortOrder {
+  ASC = '0',
+  DESC = '1',
+}
+
+// ============ 视图数据类型（合并接口 + 行情后，供 View 消费） ============
+// 保留原始字段，不在数据层预先格式化/预先判断涨跌色；HTTP 占位行允许行情字段暂缺。
+export interface RankItem {
+  code: string;
+  market: string;
+  name: string;
+  price?: number;
+  // 涨跌幅（%数值，如 3.21 表示 +3.21%）。行情推送里固定字段，任何 Tab 下都存在，
+  // 用于「最新价」列的取色，也是 涨幅/跌幅 Tab 第三列的数据来源。
+  price_chg?: number;
+  // 涨速/跌速（%数值）。仅 riseSpeed/fallSpeed Tab 下有值。
+  chg_speed?: number;
+  // 成交额（原始数值，未换算单位）。仅 turnOver Tab 下有值。
+  turnover?: number;
+  // 日增仓（原始数值，未换算单位）。仅 increPosit Tab 下有值。
+  incre_posit?: number;
+}
+
+// 当前市场排名卡片的完整展示数据；网络/行情更新后整体替换以触发 UI 刷新。
+export interface CardData {
+  tableList: RankItem[];
+}
+
+export interface TabMetric {
+  id: MetricId;
+  label: ResourceStr;
+  api: string; // HTTP 接口 quote_type 参数用
+  hqId: number; // 行情订阅 sortid 用
+  sortOrder: string; // 行情排序方向 '0' 升序 '1' 降序
+  hasChildren: boolean; // Vue 用 children 数组本身判断，这里简化为布尔标记
+}
+
+export interface PeriodRange {
+  id: PeriodId;
+  label: ResourceStr;
+  api: string;
+  hqId: number;
+}
+
+// ============ 后端接口原始响应类型（recommend_futures） ============
+// 对应 docs/cards/interfaces.md「一、HTTP 接口 - 1. 市场排名列表」
+
+export interface RecommendFuturesItem {
+  contract_code: string;
+  contract_name: string;
+  market: string;
+}
+
+export interface RecommendFuturesResponse {
+  code: number;
+  data: RecommendFuturesItem[];
+}