fix(config): set ClickHouse to disabled by default and update related documentation

internal/infra/config/config.go

@@ -130,9 +130,8 @@ func applyClickHouseDefaults(c *configModel) {
 		}
 		// Keep Enabled=true from env and continue applying host/pool defaults.
 	}
-	if !c.ClickHouse.Enabled {
-		c.ClickHouse.Enabled = true
-	}
+	// 未显式启用（缺省或 enabled: false）时保持关闭，不再强制打开；
+	// 显式启用后补齐连接默认参数。
 	if c.ClickHouse.Database == "" {
 		c.ClickHouse.Database = "openflare"
 	}

internal/infra/config/config_test.go

@@ -12,3 +12,35 @@ func TestApplyEnvOverridesRedisMaintNotifications(t *testing.T) {
 		t.Fatal("REDIS_MAINT_NOTIFICATIONS=true was not applied")
 	}
 }
+
+// TestApplyClickHouseDefaultsRespectsDisabledConfig 回归：配置未显式启用（缺省或
+// enabled: false）时 ClickHouse 必须保持关闭，不得被 applyClickHouseDefaults 强制打开。
+// CLICKHOUSE_ENABLED=true 仅用于绕过测试分支（isTest 默认强制关闭），以便测真实默认逻辑。
+func TestApplyClickHouseDefaultsRespectsDisabledConfig(t *testing.T) {
+	t.Setenv("CLICKHOUSE_ENABLED", "true")
+
+	cfg := &configModel{ClickHouse: clickHouseConfig{Enabled: false}}
+	applyClickHouseDefaults(cfg)
+
+	if cfg.ClickHouse.Enabled {
+		t.Fatal("ClickHouse must stay disabled when config does not enable it")
+	}
+}
+
+// TestApplyClickHouseDefaultsEnablesWhenConfigured 显式 enabled: true 时保持启用并补齐默认连接参数。
+func TestApplyClickHouseDefaultsEnablesWhenConfigured(t *testing.T) {
+	t.Setenv("CLICKHOUSE_ENABLED", "true")
+
+	cfg := &configModel{ClickHouse: clickHouseConfig{Enabled: true}}
+	applyClickHouseDefaults(cfg)
+
+	if !cfg.ClickHouse.Enabled {
+		t.Fatal("ClickHouse must stay enabled when explicitly configured")
+	}
+	if cfg.ClickHouse.Database != "openflare" {
+		t.Fatalf("database default not applied: %q", cfg.ClickHouse.Database)
+	}
+	if len(cfg.ClickHouse.Hosts) != 1 || cfg.ClickHouse.Hosts[0] != "127.0.0.1:9000" {
+		t.Fatalf("hosts default not applied: %v", cfg.ClickHouse.Hosts)
+	}
+}