#5094: Fix browser set headers CLI option collision

## Fix browser set headers CLI option collision ### Background The `browser set headers` command previously the `--json` option to accept header input. However, the parent `browser` command already defines the `--json` flag for controlling output format. This option name collision resulted in ambiguous parsing behavior across different invocation environments, causing the headers input to be misinterpreted or ignored. --- ### Changes This PR addresses the issue by: - **Disambiguating CLI options** - Rename the headers input option from `--json` to `--headers-json` with a more specific naming - Clearly separate header input semantics from the parent output formatting flag - **Clarifying CLI usage** - Update command usage to reflect the new option name and expected input value type as a JSON string --- ### Example Usage ```bash openclaw browser set headers --headers-json '{"User-Agent":"my-agent"}' ``` --- ### Follow-up The official documentation needs to update seprately to reflect this naming change. And this is **important**. <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This PR updates the `browser set headers` subcommand to avoid a flag-name collision with the parent `browser --json` output flag by renaming the header-input option from `--json` to `--headers-json` in `src/cli/browser-cli-state.ts`. However, the implementation currently still reads the payload from `opts.json`, so the renamed flag will not be honored and the command is likely broken until it reads `opts.headersJson` (commander camel-cases option names). <h3>Confidence Score: 2/5</h3> - This PR is not safe to merge as-is because the renamed CLI flag is not actually wired up in the handler. - Although the intent (avoid `--json` collision) is correct, the handler still parses `opts.json` instead of the new commander option property, so the primary functionality likely breaks at runtime for users of `--headers-json`. - src/cli/browser-cli-state.ts <!-- greptile_other_comments_section --> _{(4/5) You can add custom instructions or style guidelines for the agent [here](https://app.greptile.com/review/github)!} <!-- /greptile_comment -->