Track v1.2 documentation follow-ups

[fengjiachun]

Scope

Track unfinished documentation work for user-facing changes included in v1.2.0-beta.1.

Requests whose upstream changes are not included in v1.2.0-beta.1 are outside the scope of this issue.

Documentation work

• Update docs for feat: new HTTP API for formatting SQL #2025 — Document the SQL formatting HTTP API introduced by GreptimeDB #6691. Owner: @fengjiachun
• Fix sparse primary key encoding documentation for v1.2 #2717 — Fix sparse primary key encoding documentation for v1.2. Owner: @sunng87
• Document v1.2 breaking changes in the upgrade guide #2718 — Document v1.2 breaking changes in the upgrade guide. Owner: @fengjiachun
• Document the streaming EXPLAIN ANALYZE HTTP API #2719 — Document the streaming EXPLAIN ANALYZE HTTP API. Owner: @discord9
• Document Prometheus Remote Write v2 and native histograms #2720 — Document Prometheus Remote Write v2 and native histograms. Owner: @shuiyisong
• Document the MySQL object store backend #2721 — Document the MySQL object store backend. Owner: @fengys1996
• Document the max_row_group_row_count table option #2722 — Document the max_row_group_row_count table option. Owner: @evenyag
• Add an Events query guide #2723 — Add an Events query guide for greptime_private.events. Owner: @WenyXu
• Document the Kafka WAL create_index option and v1.2 default #2724 — Document the Kafka WAL create_index option and v1.2 default. Owner: @WenyXu

Each child issue contains its upstream source links, documentation contract, and acceptance criteria.

Version and language scope

Unless a child issue explicitly narrows the scope, update:

• English Nightly
• Chinese Nightly
• English v1.2
• Chinese v1.2

Completion criteria

• All tracked behavior is documented accurately for v1.2.
• Nightly and v1.2 documentation remain aligned where the behavior applies to both.
• English and Chinese content is aligned in meaning.
• Affected locale builds pass.
• All checklist issues above are closed.