fix(plugin): make proxy stub property access an explicit error

A proxy stub declares none of the real class's instance properties, and the
`__get`/`__set` forwarders were emitted only for classes that declare a public
one. Every other property access therefore got PHP's own answer for an
undeclared property — null on a read, a dynamic property on a write — so plugin
code reading state the entity holds ran on with null and failed somewhere else
entirely, or not at all.

Emit the forwarders on every root stub, add `__isset`/`__unset` alongside them
so `isset()` cannot answer false silently either, and serve all four from one
dispatcher that answers the state the Rust-side entity exposes and rejects every
other name.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

0 files changed, 0 insertions, 0 deletions