DEBUG BUILD — probe path instrumented (not a release, not a fix)

Diagnostic build for ApolloVibe#2. It does not attempt to fix anything — it reports where the hang happens.

Adds [PROBE] markers at info level (not verbose, which enables AMF's own debug output) around init_codec_options, avcodec_open2 entry and success, and every stage of ~avcodec_encode_session_t().

That destructor's drain loop is while (avcodec_receive_packet(...) == 0); — an empty-bodied spin, which is what a pinned core looks like. It is bounded at 200,000 packets here with an explicit abort line, so if it is the fault this build escapes it rather than hanging.

Built from 55231bdf on debug/probe-instrumentation. sunshine.exe SHA256 begins 076ddfee820851fe.

⚠️ Pre-release on purpose — nothing that auto-installs ApolloVibe will pick this up.