chore(parsers): minor leftovers from the #1538 audit — annotation line convention, Ruby class/global vars, Ruby variable values #1660

The 'Minor' section of #1538, split out so the parent audit can close. Each is small and independent; the substantive sections all landed (#1628, #1654, #1657, #1659).

1. kotlin.py:1223/:1342, php.py:280/:213 — line_number points at the annotation/attribute line rather than the declaration. python.py handles this deliberately via decorated_definition and csharp.py was aligned in fix(parsers): final #1538 audit batch — spurious records, PHP enums, C macros/enum members #1659 — Kotlin and PHP should follow the same declaration-line convention.
2. ruby.py:38-47, :516-522 — @@class_vars and $globals are never captured (the variables query only matches plain/instance assignments).
3. ruby.py:487-507 — variable value is always None: node.parent returns a fresh Python wrapper each access, so id(current) differs for the same underlying node and the @name/@value captures land in different buckets (n1 == n2 is True while id(n1) == id(n2) is False — bucket by (start_byte, end_byte) instead).

(The C/C++ macro end_line off-by-one from the same list was fixed in #1628/#1659.)