feat(V1-API): implement TREX-Basic consumer API contract with encryption and persistence

- Add V1 API endpoints: assets, ledger, user-info
- Implement Fernet-based credential payload encryption (req-010)
- Extend health response schema with runtime info (req-004)
- Add service token runtime ID issuance (req-005)
- Implement database schema migration for V1 API (req-009)
- Add comprehensive test coverage for V1 endpoints
- Update SRS with 10 new requirements (REQ-004 through REQ-011)
- Create batch planning, design, and verification for BAT-001
- Integrate review-discovery StagePilot skill
- Update documentation indices and baseline specs

app/schemas/v1.py

@@ -0,0 +1,82 @@
+"""Schemas for v1 (Consumer-Driven Contract) API endpoints."""
+
+from __future__ import annotations
+
+from datetime import datetime
+from decimal import Decimal
+from typing import Literal
+
+from pydantic import BaseModel, Field
+
+
+# ---------------------------------------------------------------------------
+# GET /v1/assets
+# ---------------------------------------------------------------------------
+
+class AssetItem(BaseModel):
+    asset_id: str
+    broker: str
+    market: str | None = None
+    symbol: str
+    name: str
+    status: str
+    cash_balance: float
+    asset_quantity: float
+    price: float
+    profit_buffer: float
+    active_strategy_id: str | None = None
+    available_strategies: list[str] | None = None
+    tags: list[str] | None = None
+    owner_user_id: str | None = None
+    created_at: datetime | None = None
+    updated_at: datetime | None = None
+    last_trade_at: datetime | None = None
+
+
+class AssetsResponse(BaseModel):
+    assets: list[AssetItem]
+    total: int
+
+
+# ---------------------------------------------------------------------------
+# GET /v1/user_info
+# ---------------------------------------------------------------------------
+
+class UserInfoResponse(BaseModel):
+    user_id: str
+    username: str
+    email: str | None = None
+    permission: str
+    is_active: bool
+    disabled_reason: str | None = None
+    runtime_id: str
+
+
+# ---------------------------------------------------------------------------
+# POST /v1/assets/{asset_id}/ledger/trades
+# ---------------------------------------------------------------------------
+
+class LedgerTradeRequest(BaseModel):
+    order_id: str = Field(..., min_length=1)
+    execution_id: str = Field(..., min_length=1)
+    side: Literal["buy", "sell"]
+    quantity: Decimal = Field(..., gt=0)
+    price: Decimal = Field(..., gt=0)
+    fee_amount: Decimal = Field(default=Decimal("0"), ge=0)
+    tax_amount: Decimal = Field(default=Decimal("0"), ge=0)
+    executed_at: datetime
+
+
+class LedgerTradeResponse(BaseModel):
+    ledger_entry_id: int
+    asset_id: str
+    order_id: str
+    execution_id: str
+    side: str
+    quantity: float
+    price: float
+    fee_amount: float
+    tax_amount: float
+    executed_at: datetime
+    recorded_at: datetime | None = None
+    created: bool