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>

docs/help/environment.md

@@ -82,6 +82,12 @@ See [Configuration: Env var substitution](/gateway/configuration#env-var-substit
 | `OPENCLAW_STATE_DIR`   | Override the state directory (default `~/.openclaw`).                                                                                                                            |
 | `OPENCLAW_CONFIG_PATH` | Override the config file path (default `~/.openclaw/openclaw.json`).                                                                                                             |
 
+## Logging
+
+| Variable             | Purpose                                                                                                                                                                                      |
+| -------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `OPENCLAW_LOG_LEVEL` | Override log level for both file and console (e.g. `debug`, `trace`). Takes precedence over `logging.level` and `logging.consoleLevel` in config. Invalid values are ignored with a warning. |
+
 ### `OPENCLAW_HOME`
 
 When set, `OPENCLAW_HOME` replaces the system home directory (`$HOME` / `os.homedir()`) for all internal path resolution. This enables full filesystem isolation for headless service accounts.

docs/logging.md

@@ -118,6 +118,8 @@ All logging configuration lives under `logging` in `~/.openclaw/openclaw.json`.
 - `logging.level`: **file logs** (JSONL) level.
 - `logging.consoleLevel`: **console** verbosity level.
 
+You can override both via the **`OPENCLAW_LOG_LEVEL`** environment variable (e.g. `OPENCLAW_LOG_LEVEL=debug`). The env var takes precedence over the config file, so you can raise verbosity for a single run without editing `openclaw.json`. You can also pass the global CLI option **`--log-level <level>`** (for example, `openclaw --log-level debug gateway run`), which overrides the environment variable for that command.
+
 `--verbose` only affects console output; it does not change file log levels.
 
 ### Console styles