[docs](file-cache) Document query-level cache write limit

[bobhan1]

Summary

• document the file_cache_query_limit_bytes session variable introduced by [feature](file-cache) Disable cache writes after remote scan threshold doris#65058
• document the enable_file_cache_query_limit_segment_meta BE configuration and its default metadata-accounting behavior
• distinguish the new no-more-write threshold from the existing eviction-based file_cache_query_limit_percent quota
• add usage, per-BE scope, cache-block granularity, Profile counters, caveats, and tuning guidance to the File Cache and Lakehouse Data Cache pages
• synchronize the current and 4.x English, Chinese, and Japanese pages
• state in every 4.x page that the byte-threshold feature is supported only in Doris 4.1.x and is not supported in Doris 4.0.x

Scope

This PR updates the File Cache and Lakehouse Data Cache pages across the current and 4.x English, Chinese, and Japanese documentation. The 4.x pages explicitly identify the byte-threshold feature as available only in Doris 4.1.x.

Validation

• git diff --check
• python3 scripts/check_md_links_single.py <file> --no-external for all 12 changed pages
• front matter JSON, Markdown fence, and admonition balance checks for all 12 changed pages
• matching current/4.x section checks across all three languages, allowing only the 4.1.x-specific version note

A full Docusaurus build was not run for this documentation-only change.

Versions

• dev
• 4.x
• 3.x
• 2.1 or older (not covered by version/language sync gate)

Languages

• Chinese
• English
• Japanese candidate translation needed

Docs Checklist

• Checked by AI
• Test Cases Built
• Updated required version and language counterparts, or explained why not
• If only one language changed, confirmed whether source/translation counterparts need sync