#14551: docs(zalouser): add OpenZCA as free alternative to zca-cli

## Summary - Adds [OpenZCA](https://openzca.com) as a free, open-source alternative to [zca-cli](https://zca-cli.dev) in all zalouser documentation - Both implementations are fully compatible with the zalouser plugin - Updated install instructions across 5 files (EN + zh-CN) ### Files changed - `extensions/zalouser/README.md` — full install instructions for both options (npm, shell scripts, npx) - `docs/plugins/zalouser.md` — prerequisite section - `docs/channels/zalouser.md` — prerequisite section - `docs/zh-CN/plugins/zalouser.md` — Chinese translation - `docs/zh-CN/channels/zalouser.md` — Chinese translation ## Test plan - [x] Verify all links resolve correctly ([openzca.com](https://openzca.com), [zca-cli.dev](https://zca-cli.dev)) - [x] Verify install commands work: `npm i -g openzca@latest` - [x] Confirm docs render correctly in the docs site --- > [!NOTE] > This PR is AI-assisted (Claude Code). Changes are documentation-only and have been reviewed for accuracy. Lightly tested (link verification). <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This PR updates the Zalo Personal (zalouser) documentation to mention two compatible ways to provide the required `zca` CLI on the Gateway: the paid `zca-cli` and the free/open-source OpenZCA. It adds install snippets for both options across the English and zh-CN plugin/channel docs and expands `extensions/zalouser/README.md` with OpenZCA install methods (npm, shell scripts, PowerShell, npx) alongside the existing zca-cli instructions. <h3>Confidence Score: 4/5</h3> - Safe to merge after a small docs consistency fix. - Changes are documentation-only and primarily add alternative install instructions; the only clear issue found is an internal inconsistency where the extension README intro still implies zca-cli is required while later sections state OpenZCA is also supported. - extensions/zalouser/README.md <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->