feat(ws2): ADR-093 路由統一 — BIGINT + NotificationMatrix + feature flag

## 修復

### T2.1 BigInteger overflow 修復
- `db/models.py`: telegram_chat_id Integer → BigInteger
  （原 int32 無法容納群組 ID -1003711974679）

### T2.2 移除 CAST workaround
- `approval_db.py:739`: 移除 CAST(:telegram_chat_id AS BIGINT)
  ORM 已正確使用 BigInteger，workaround 可退役

### T2.3 Redis key 一致性修復
- `heartbeat_report_service.py:575`: telegram:polling_leader → telegram:polling:leader
  （telegram_gateway.py 使用冒號分隔，heartbeat 用底線是 bug）

## 新增

### T2.4 notification_matrix.py
- `services/notification_matrix.py`: ADR-093 路由矩陣
  - Destination(DM/GROUP/BOTH) + RoutingRule dataclass
  - NOTIFICATION_ROUTING dict（TYPE-1 ~ TYPE-8M 完整映射）
  - resolve_chat_ids(type, dm, group, *, tg_group_cutover=False) 灰階切流 API

### T2.5 telegram_gateway.py feature flag 保護
- line 43: 加 notification_matrix import
- line 1827-1834: TG_GROUP_CUTOVER=False 時維持舊行為
  TG_GROUP_CUTOVER=True 時解除 _interactive_types 黑名單，由矩陣控制

### T2.6 Migration SQL
- `migrations/adr093_notification_routing.sql`:
  - CREATE TABLE approval_records (telegram_chat_id BIGINT)
  - CREATE ROLE awoooi_migrator (IF NOT EXISTS)
  - 含舊環境 ALTER COLUMN int→bigint 保護

## 測試同步
- `tests/integration/setup_test_schema.sql`: telegram_chat_id BIGINT

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/api/src/services/notification_matrix.py

@@ -0,0 +1,81 @@
+"""
+Notification routing matrix — ADR-093
+======================================
+單一矩陣決定每種通知類型的發送目標，取代 telegram_gateway.py 內 24 處硬碼 chat_id。
+
+設計原則：
+- tg_group_cutover=False（預設）時維持舊行為，灰階切流用
+- tg_group_cutover=True 時由矩陣完全控制路由
+- 未知通知類型預設發群組
+
+2026-04-25 ogt + Claude Sonnet 4.6
+"""
+from __future__ import annotations
+from dataclasses import dataclass
+from enum import Enum
+
+
+class Destination(str, Enum):
+    DM = "dm"           # OPENCLAW_TG_CHAT_ID (個人 DM)
+    GROUP = "group"     # SRE_GROUP_CHAT_ID
+    BOTH = "both"       # 兩者都發（群組版去按鈕）
+
+
+@dataclass(frozen=True)
+class RoutingRule:
+    destination: Destination
+    strip_buttons_for_group: bool = False   # BOTH 時群組版是否去除 Callback Button
+
+
+# ADR-093 D1-D4 路由矩陣
+# TYPE-5S / TYPE-7E 暫留 DM（v2 再討論）
+NOTIFICATION_ROUTING: dict[str, RoutingRule] = {
+    "TYPE-1":  RoutingRule(Destination.GROUP),
+    "TYPE-2":  RoutingRule(Destination.BOTH, strip_buttons_for_group=True),
+    "TYPE-3":  RoutingRule(Destination.GROUP),
+    "TYPE-4":  RoutingRule(Destination.GROUP),
+    "TYPE-4D": RoutingRule(Destination.GROUP),
+    "TYPE-5S": RoutingRule(Destination.DM),
+    "TYPE-6B": RoutingRule(Destination.GROUP),
+    "TYPE-7E": RoutingRule(Destination.BOTH, strip_buttons_for_group=False),
+    "TYPE-8M": RoutingRule(Destination.GROUP),
+}
+
+_DEFAULT_RULE = RoutingRule(Destination.GROUP)
+
+
+def get_routing_rule(notification_type: str) -> RoutingRule:
+    """根據通知類型回傳路由規則。未知類型預設發群組。"""
+    return NOTIFICATION_ROUTING.get(notification_type, _DEFAULT_RULE)
+
+
+def resolve_chat_ids(
+    notification_type: str,
+    dm_chat_id: str,
+    group_chat_id: str,
+    *,
+    tg_group_cutover: bool = False,
+) -> list[str]:
+    """
+    回傳此通知應發送的 chat_id 清單。
+    tg_group_cutover=False 時維持原本的 DM only 行為（灰階切流用）。
+    """
+    if not tg_group_cutover:
+        # Feature flag 關閉 → 維持舊行為（DM only for interactive, group for info）
+        interactive = {"TYPE-3", "TYPE-4", "TYPE-4D", "TYPE-8M"}
+        if notification_type in interactive:
+            return [dm_chat_id] if dm_chat_id else []
+        return [group_chat_id] if group_chat_id else []
+
+    rule = get_routing_rule(notification_type)
+    if rule.destination == Destination.DM:
+        return [dm_chat_id] if dm_chat_id else []
+    elif rule.destination == Destination.GROUP:
+        return [group_chat_id] if group_chat_id else []
+    else:  # BOTH
+        result = []
+        if group_chat_id:
+            result.append(group_chat_id)
+        if dm_chat_id:
+            result.append(dm_chat_id)
+        return result