feat: implement Firebird\Event class methods (Phase H)

[satwareAG-ironMike]

Problem

Firebird\Event is registered in fbird_classes.c:1394 with NULL methods (INIT_CLASS_ENTRY(ce, "Firebird\\Event", NULL)). The class is returned by fbird_set_event_handler but no methods are accessible from PHP. Comment says "wired in Phase H".

Acceptance Criteria

• Firebird\Event has at minimum: wait(float $timeout = -1): bool, cancel(): void, getEventNames(): array
• fbird_events.c migrated to use Firebird\Event object (no le_event resource)
• Stub updated in stubs/firebird-classes.php and phpstan/fbird.stub.php
• Tests added for Firebird\Event methods

Source

QA Audit 2026-04-09 - Finding C11 (Priority P3 - Phase H)