feat: 拆分 worker 架构并增强 assistant 安全保护

- 新增 daemon/channel/assistant/function/scheduler/logging worker 架构和 JetStream 消息协议

- 修复邮件通知误入 assistant、迁移 checksum、日志 subject 和工具调用无限循环风险

- 新增 assistant 工具轮次熔断、工具结果截断和提示词软收敛规则

- 补充邮件推送关键字、可信发件人配置、升级日志和验证测试

ias-db/migrations/20260709003000_architecture_split_schedules.sql

@@ -0,0 +1,57 @@
+CREATE TABLE IF NOT EXISTS ias_schedules (
+    id BIGSERIAL PRIMARY KEY,
+    name VARCHAR(255) NOT NULL,
+    schedule_type VARCHAR(32) NOT NULL,
+    expression TEXT NOT NULL,
+    target_topic TEXT NOT NULL,
+    payload JSONB NOT NULL DEFAULT '{}',
+    enabled BOOLEAN NOT NULL DEFAULT TRUE,
+    last_fired_at TIMESTAMPTZ,
+    next_fire_at TIMESTAMPTZ NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    CONSTRAINT ias_schedules_type_check CHECK (schedule_type IN ('cron', 'interval'))
+);
+
+CREATE INDEX IF NOT EXISTS idx_ias_schedules_due
+    ON ias_schedules(next_fire_at)
+    WHERE enabled = TRUE;
+
+CREATE UNIQUE INDEX IF NOT EXISTS idx_ias_schedules_name_unique
+    ON ias_schedules(name);
+
+CREATE TABLE IF NOT EXISTS ias_schedule_fires (
+    fire_id TEXT PRIMARY KEY,
+    schedule_id BIGINT NOT NULL REFERENCES ias_schedules(id) ON DELETE CASCADE,
+    fire_time TIMESTAMPTZ NOT NULL,
+    status VARCHAR(32) NOT NULL DEFAULT 'publishing',
+    attempt_count INTEGER NOT NULL DEFAULT 0,
+    published_at TIMESTAMPTZ,
+    error TEXT,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_ias_schedule_fires_schedule_time
+    ON ias_schedule_fires(schedule_id, fire_time DESC);
+
+CREATE INDEX IF NOT EXISTS idx_ias_schedule_fires_reclaim
+    ON ias_schedule_fires(status, updated_at)
+    WHERE status IN ('failed', 'publishing');
+
+CREATE TABLE IF NOT EXISTS ias_assistant_turns (
+    operation_key TEXT PRIMARY KEY,
+    channel TEXT NOT NULL,
+    account_id TEXT NOT NULL,
+    from_user_id TEXT NOT NULL,
+    turn_id TEXT NOT NULL,
+    trace_id TEXT NOT NULL DEFAULT '',
+    status VARCHAR(32) NOT NULL DEFAULT 'active',
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    CONSTRAINT ias_assistant_turns_status_check
+        CHECK (status IN ('active', 'completed', 'cancelled'))
+);
+
+CREATE INDEX IF NOT EXISTS idx_ias_assistant_turns_status_updated
+    ON ias_assistant_turns(status, updated_at DESC);