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/migrations/adr093_notification_routing.sql

@@ -0,0 +1,78 @@
+-- ADR-093: Notification Matrix Migration
+-- =========================================
+-- 1. 建立 approval_records 表（BIGINT telegram_chat_id，支援群組負數 ID）
+-- 2. 建立 awoooi_migrator 角色
+-- 2026-04-25 ogt + Claude Sonnet 4.6
+
+-- awoooi_migrator 角色（ADR-090b 計畫的實作）
+DO $$
+BEGIN
+    IF NOT EXISTS (SELECT FROM pg_roles WHERE rolname = 'awoooi_migrator') THEN
+        CREATE ROLE awoooi_migrator LOGIN;
+    END IF;
+END
+$$;
+
+GRANT CONNECT ON DATABASE awoooi_prod TO awoooi_migrator;
+GRANT USAGE ON SCHEMA public TO awoooi_migrator;
+GRANT CREATE ON SCHEMA public TO awoooi_migrator;
+
+-- approval_records 主表（全新建立，直接用 BIGINT）
+-- 注意：test schema setup_test_schema.sql 同步更新為 BIGINT
+CREATE TABLE IF NOT EXISTS approval_records (
+    id                  VARCHAR(36)      PRIMARY KEY,
+    action              VARCHAR(500)     NOT NULL,
+    description         TEXT             NOT NULL,
+    status              VARCHAR(20)      NOT NULL DEFAULT 'PENDING',
+    risk_level          VARCHAR(20)      NOT NULL,
+    required_signatures INTEGER          DEFAULT 1,
+    current_signatures  INTEGER          DEFAULT 0,
+    signatures          JSON             DEFAULT '[]',
+    blast_radius        JSON             DEFAULT '{}',
+    dry_run_checks      JSON             DEFAULT '[]',
+    requested_by        VARCHAR,
+    rejection_reason    TEXT,
+    extra_metadata      JSON             DEFAULT '{}',
+    fingerprint         VARCHAR,
+    hit_count           INTEGER          DEFAULT 1,
+    last_seen_at        TIMESTAMPTZ,
+    approval_level      VARCHAR          DEFAULT 'standard',
+    approval_votes      JSONB,
+    required_votes      INTEGER          DEFAULT 1,
+    incident_id         VARCHAR,
+    telegram_message_id INTEGER,
+    telegram_chat_id    BIGINT,          -- 支援群組負數 ID（原 INTEGER 會 int32 overflow）
+    matched_playbook_id VARCHAR(36),
+    created_at          TIMESTAMPTZ      NOT NULL DEFAULT NOW(),
+    updated_at          TIMESTAMPTZ      NOT NULL DEFAULT NOW(),
+    expires_at          TIMESTAMPTZ,
+    resolved_at         TIMESTAMPTZ
+);
+
+-- 若表已存在（舊環境），執行欄位型別升級
+DO $$
+BEGIN
+    IF EXISTS (
+        SELECT 1 FROM information_schema.columns
+        WHERE table_name = 'approval_records'
+          AND column_name = 'telegram_chat_id'
+          AND data_type = 'integer'
+    ) THEN
+        ALTER TABLE approval_records
+            ALTER COLUMN telegram_chat_id TYPE BIGINT;
+        RAISE NOTICE 'approval_records.telegram_chat_id upgraded INTEGER → BIGINT';
+    END IF;
+END
+$$;
+
+-- 索引
+CREATE INDEX IF NOT EXISTS idx_approval_records_status ON approval_records(status);
+CREATE INDEX IF NOT EXISTS idx_approval_records_incident ON approval_records(incident_id);
+CREATE INDEX IF NOT EXISTS idx_approval_records_fingerprint ON approval_records(fingerprint);
+CREATE INDEX IF NOT EXISTS idx_approval_records_playbook ON approval_records(matched_playbook_id);
+
+GRANT SELECT, INSERT, UPDATE, DELETE ON approval_records TO awoooi;
+GRANT SELECT, INSERT, UPDATE ON approval_records TO awoooi_migrator;
+
+COMMENT ON TABLE approval_records IS 'ADR-093 2026-04-25: telegram_chat_id 改 BIGINT 支援群組負數 ID';
+COMMENT ON COLUMN approval_records.telegram_chat_id IS 'BIGINT: 支援 SRE 群組 ID (-1003711974679) 不 overflow';