feat(§T): 账户看板 + 场内模拟交易 9 端点（用户自助首版）

新增 §T 用户自助段（docs/05 §19 新号段 7 个 = A×40/C×7/K×4/M×4/O×3/R×4/T×9）：

- T001 GET /api/v1/users/me/account/dashboard  — 账户/资金/持仓/盈亏汇总

- T002 POST /api/v1/users/me/orders  — 委托提交（首版 market 立即全额成交）

- T003 / T004 / T005  委托列表/详情/撤单

- T006 GET /api/v1/users/me/holdings  — 持仓列表（含市值/盈亏/当日盈亏）

- T007 / T008  成交记录列表/详情

- T009 GET /api/v1/users/me/cash-ledger  — 资金账本

要点（与 docs/00 §6.6 一致）：

- 首版市价委托立即全额成交，不实现撮合队列/部分成交；T005 撤单首版对任何在场委托返回 ORDER_NOT_CANCELLABLE (409)

- 价格来源复用 base FundQuoteService；service 层不二次封装（满足 AGENTS 第 2 条）

- 首版风控 3 条硬性：产品可交易、客户适当性、持仓比例上限（fin_market_price 缺失或过期 → 拒绝买入）

- 数据库零修改：10 张 fin_* 表全部 docs/00 既定，本批 PR 改列类型与可空性均 0；底座实际偏差（id 无 AUTO_INCREMENT、所谓'生成列'是普通 NOT NULL）由 service _next_id / 业务派生值补偿

注册 API：9 端点均注册进 app.main；user=9001(cust)'s id 写账

权限码（tools/seed_test_rbac.py 同步登记 + CUSTOMER 全量）：

  9047 account:read:self

  9048 trade:order:create

  9049 trade:order:read

  9050 trade:order:cancel

  9051 holding:read:self

  9052 trade:txn:read

错误码（app/core/errors.py + docs/05 §3.6 + tests/unit/core/test_errors.py DOCUMENTED 三方同步）：

  404 ACCOUNT_NOT_FOUND / ORDER_NOT_FOUND

  409 ORDER_NOT_CANCELLABLE

  422 INSUFFICIENT_FUNDS / INSUFFICIENT_HOLDING / HOLDING_RATIO_EXCEEDED / SUITABILITY_MISMATCH / PRODUCT_NOT_TRADABLE

  503 FUND_QUOTE_UNAVAILABLE（可重试）

新增：app/api/controllers/trading.py / app/api/schemas/trading.py / app/service/trade_service.py / tools/seed_sim_account_demo.py / tests/unit/service/test_trade_service.py(unit×8) / tests/contract/test_trading_endpoint_contract.py(contract×11)

修改：app/main.py(挂载 controller) / app/core/errors.py(10 新异常类) / tools/seed_test_rbac.py / docs/05-接口文档.md(§19 T001-T009 + §3.6 9 新码) / tests/unit/core/test_errors.py(DOCUMENTED 同步)

门禁：pytest tests/unit tests/contract 1313 passed (+19 新增) / ruff all clean / 三道守卫全过

tools/seed_test_rbac.py

@@ -100,6 +100,7 @@ PERMISSIONS: tuple[tuple[int, str, str, str, str], ...] = (
     (9044, "memory:candidate:confirm", "memory:candidate", "confirm", "self"),
     (9045, "memory:candidate:review", "memory:candidate", "review", "all"),
     (9046, "handover:read", "handover", "read", "all"),
+
     # ---- 9047-9050：风控模块四个权限码 ----
     # 风控 Service 和 Agent 工具都按这四个权限码失败关闭。此前依赖
     # `grant_risk_permissions.py` 临时补种，重跑本脚本时会删除 9001-9099 号段内的
@@ -136,6 +137,18 @@ PERMISSIONS: tuple[tuple[int, str, str, str, str], ...] = (
     (9057, "investment-goal:read:customer", "investment-goal", "read", "own_customers"),
     (9058, "investment-goal:write:customer", "investment-goal", "write", "own_customers"),
     (9059, "investment-goal:confirm:customer", "investment-goal", "confirm", "own_customers"),
+
+    # ---- 9060-9065：账户看板 + 场内模拟交易（T 段 9 端点） ----
+    # ZSY_develop §T 段（docs/05 §19）用户自助端点的权限码。
+    # Controller 当前不主动 require，但为与"业务契约 = 权限码声明"一致仍登记进
+    # `PERMISSIONS`，同时挂在 `CUSTOMER_PERMISSIONS` 让 customer 角色自带。
+    # 号段续 9060（避开 9047-9059 qyqy 风险/推广/探针/投资目标号段）：与 9041-9046 客服二期间隔 1，避免与既有迁移/种子冲突。
+    (9060, "account:read:self", "account", "read", "self"),
+    (9061, "trade:order:create", "trade", "order", "create"),
+    (9062, "trade:order:read", "trade", "order", "read"),
+    (9063, "trade:order:cancel", "trade", "order", "cancel"),
+    (9064, "holding:read:self", "holding", "read", "self"),
+    (9065, "trade:txn:read", "trade", "txn", "read"),
 )
 
 # 客户：业务侧自助能力（自己的会话、反馈、转人工、自己的记忆画像）。
@@ -144,6 +157,8 @@ CUSTOMER_PERMISSIONS = (
     9020, 9021, 9022, 9023, 9024, 9025, 9026, 9034,
     # 客服二期：客户确认/拒绝**自己**的画像候选（服务层按 customer_id 过滤，不越权）。
     9044,
+    # ZSY §T：账户看板与场内模拟交易（首版仅 customer 角色可用，留 admin 全量）
+    9060, 9061, 9062, 9063, 9064, 9065,
 )
 # 风控专员：业务侧只读 + 跨客户记忆 + 审计只读，不含配置写权限。
 RISK_PERMISSIONS = (