docs(transfer): add deployment guide (CurvineIO/curvine#1040)

[jlon]

Summary

Adds a dedicated Transfer deployment section for the independent Load and Export service, and aligns the Load, cache, OpenDAL, and CLI guides with Transfer client routing.

Issue Describe / Design

Related to CurvineIO/curvine#1040.

The documentation separates core cluster installation from the optional Transfer service. SQLite is documented as a single-instance deployment with persistent storage; MySQL is required before running multiple Transfer instances. Master and Worker configuration remain unchanged during client-side rollout.

Changes

Module / File	Change	Impact on existing behavior
docs/2-Deploy	Adds deployment overview plus bare-metal and Kubernetes Transfer guides.	New documentation only.
Transfer configuration reference	Documents supported [transfer] fields and defaults.	New documentation only.
Load, cache, CLI, and OpenDAL guides	Documents Transfer routing and cv transfer operations.	Clarifies existing behavior and compatibility.
i18n/zh-cn	Adds matching Chinese documentation.	New documentation only.

Test verified

Test case	Result	Notes
npm run build	PASS	Built English and Chinese documentation sites.
git diff --check	PASS	No whitespace errors in the change.

Dependencies

• Related PRs: None
• Related issues: [FEATURE] Decouple LoadJob execution from master curvine#1040
• Blocks / blocked by: None