Feat/logger support log level validation0222 (#23436)

* 1、环境变量**：新增 `OPENCLAW_LOG_LEVEL`，可取值 `silent|fatal|error|warn|info|debug|trace`。设置后同时覆盖**文件日志**与**控制台**的级别，优先级高于配置文件。
2、启动参数**：在 `openclaw gateway run` 上新增 `--log-level <level>`，对该次进程同时生效于文件与控制台；未传时仍使用环境变量或配置文件。

* fix(logging): make log-level override global and precedence-safe

---------

Co-authored-by: Peter Steinberger <steipete@gmail.com>

src/cli/argv.test.ts

@@ -39,6 +39,11 @@ describe("argv helpers", () => {
       argv: ["node", "openclaw", "--profile", "work", "-v"],
       expected: true,
     },
+    {
+      name: "root -v alias with log-level",
+      argv: ["node", "openclaw", "--log-level", "debug", "-v"],
+      expected: true,
+    },
     {
       name: "subcommand -v should not be treated as version",
       argv: ["node", "openclaw", "acp", "-v"],