[patrickbirch]

modified:   docs/install-js-lang.md
modified:   docs/js-lang-overview.md
modified:   docs/js-lang-privileges.md
modified:   docs/js-lang-procedures.md
modified:   docs/js-lang-type-conversions.md
modified:   docs/js-lang-variables.md

## Summary

• Update the js_lang documentation for Percona Server for MySQL 9.7.2 so the install, routine, privilege, variable, type-conversion, and console pages match tested server behavior.

Changes

• Install: Require the percona-server-js package, with Ubuntu and RHEL install commands. On Ubuntu, the library is installed in /usr/lib/mysql/plugin/, which is the value of plugin_dir. After installation, grant CREATE_JS_ROUTINE, including to root. Document ERROR 1227, ERROR 3529, and ERROR 6000 when reinstalling without a restart.
• Overview: Show status variables as displayed, such as Js_lang_total_heap_size. Document the JS_GET_MEMORY_USAGE_JSON() members and keys. Parameter names that are reserved words or illegal identifiers fail at CREATE with ERROR 6000 (HY000): SyntaxError: Unexpected token ')'. Add the strict-mode ReferenceError and the unavailable host objects.
• Privileges: State that CREATE_JS_ROUTINE is global and must be granted ON *.*. A schema-level grant returns ERROR 3619: Illegal privilege level specified.
• Procedures: End each example with $$;. Add DETERMINISTIC and the ERROR 1418 requirement when binary logging is enabled. Show SELECT f1(2); returning 84 and SELECT @r; returning 42. Use routine_body consistently in the syntax.
• Variables: Add js_lang.max_console_log_size (default 1048576, minimum 10240, maximum 1073741824) and describe it as a byte limit. Document silent adjustment of out-of-range values. Remove the 10 MB heap claim. A soft-limit failure returns ERROR 6000 (HY000): Memory limit exceeded. and the server keeps running.
• Type conversions: Replace SHORTINT with SMALLINT. Correct the BIGINT Number range, integer rounding, Boolean storage, JSON arrival types, charset failures, and GEOMETRY input. Split TIME, DATE, and TIMESTAMP/DATETIME behavior. Document strict-mode ERROR 1264, loose-mode clamping, and DECIMAL scale rounding with note 1265. These rules were tested on 9.7.2.
• Console API: Count js_lang.max_console_log_size in bytes, not messages. List the captured JSON log keys and the plain-log examples for assertions, groups, counters, timers, %o, and %O.