feat: add typed return annotations to all 163 procedural arginfos and 9 OOP method arginfos

[satwareAG-ironMike]

Problem

• 163 procedural function arginfos in firebird.c use untyped ZEND_ARG_INFO(0, param) without type annotations, weakening PHP reflection
• 9 OOP method arginfos in fbird_classes.c use bare ZEND_BEGIN_ARG_INFO_EX instead of ZEND_BEGIN_ARG_WITH_RETURN_TYPE_*

Acceptance Criteria

• All PHP_FE arginfos use ZEND_ARG_TYPE_INFO for typed parameters
• All OOP method arginfos use ZEND_BEGIN_ARG_WITH_RETURN_TYPE_* or ZEND_BEGIN_ARG_OBJ_RETURN_TYPE_*
• Affected methods: beginTransaction, fetch, execute, prepare, Blob::create, Blob::open, Blob::read

Source

QA Audit 2026-04-09 - Findings C8/C9 (Priority P3)