docs: agent friendly sql reference

[ULookup]

What type of PR is this?

• Enhancement
• Displaying
• Typo
• Doc Request

Which issue(s) this PR fixes:

issue #

What this PR does / why we need it:

Extends the Agent-friendly documentation rollout (originally landed in PR #676) so every page under docs/MatrixOne/Reference/SQL-Reference/** (129 pages) and docs/MatrixOne/Reference/Functions-and-Operators/** (163 pages) now carries the FULL Agent-friendly frontmatter shape — the same template used by the v3.0.11 follow-up pages such as Datetime/addtime.md and mo-tools/mo_service.md:

---
title: "..."                                                                                                                                                                                    
doc_type: reference                                                                                                                                                                             
mysql_compat: full | partial | mo_only | unknown                                                                                                                                                
differs_from_mysql: []                                                                                                                                                                          
mo_only: []                                                                                                                                                                                     
since: unknown                                                                                                                                                                                  
last_updated: 2026-05-08                                                                                                                                                                        
llms_summary: "one-line summary surfaced to llms.txt / llms-full.txt"                                                                                                                           
---                                                                                                                                                                                             

Each upgraded page also picks up a > summary blockquote under its H1, so the same one-liner is visible in both the rendered HTML and the raw .md mirror served to agents.

Every mysql_compat value was hand-verified against MySQL 8.0

All 292 pages were read in full and compared against MySQL 8.0 behavior — the automated classifier's output was used only as a starting point and corrected wherever it disagreed with the
actual docs. Notable reclassifications:

SQL-Reference

• INTERSECT, FULL JOIN → mo_only (MySQL 8.0 supports neither)
• OUTER JOIN overview → partial (it describes FULL OUTER JOIN)
• LAST_INSERT_ID → partial (multi-row INSERT returns last value, not first)
• SHOW TABLES → partial (result column is name, not Tables_in_<db>)
• EXPLAIN PREPARED → mo_only (uses EXPLAIN FORCE EXECUTE …)
• SET ROLE, CREATE ROLE, DROP ROLE, DROP USER → partial
• Data-Manipulation-Language/information-functions/current_role → partial
• SQL-Type.md → mo_only (it's an index page, not a MySQL-equivalent concept)
• CREATE FULLTEXT INDEX → partial (TAE-specific implementation)

Functions-and-Operators

• SINH → mo_only (MySQL 8.0 has no hyperbolic functions)
• LOAD_FILE → mo_only (parameter is DATALINK, not a file path)
• Datetime to-days / to-seconds / date / date-add / date-sub / date-format / extract / year / dayofyear / from-unixtime / unix-timestamp / curdate → partial (each
  body declares its own MySQL divergence)
• JSON_SET → full (MySQL 8.0 does support it — previous mo_only was wrong)
• system-ops/current_user, current_role → partial (MySQL has both names with a different output shape)
• AES_ENCRYPT / AES_DECRYPT → kept partial, but differs_from_mysql now lists the concrete block-mode and KDF gaps

Expanded differs_from_mysql / mo_only entries on CREATE USER, GRANT, REVOKE, SELECT, CREATE VIEW, CREATE TABLE, and others — covering previously-missing items like
'user'@'host' handling, ON ACCOUNT / ON DATABASE grant targets, NULLS FIRST | LAST, ALGORITHM = {UNDEFINED | MERGE | TEMPTABLE}, auto_increment step, and partition-pruning scope.

Artefacts

• docs/MatrixOne/Reference/mysql-compatibility-matrix.md regenerated from the new frontmatter — 129 rows, full=30 partial=43 mo_only=56.
• llms.txt / llms-full.txt / per-page .md mirrors refresh automatically at build time via the existing mkdocs hook.
• New helper scripts/fo-compat-classification.js captures the per-file classification table used to seed Functions-and-Operators (source of truth:
  docs/MatrixOne/Overview/feature/mysql-compatibility.md cross-checked against MySQL 8.0).
• Existing upgrader scripts/upgrade-sql-reference-frontmatter.js generalised to accept --target={sql-reference,functions-operators} and --regen-summary; its markdown-stripping logic
  fixed so identifiers like JSON_SET / STR_TO_DATE survive round-tripping.