Routes a new event_type "chat_as_soul" through dharma/recv. The Studio
preassembles the system_prompt + transcript and dispatches per-speaker;
the soul-binary just performs the LLM call as the requested speaker_slug.
No engram_compile here — each soul has its own engram (88xx) and the
Studio queries it before composing the prompt.
Also: track the previously-untracked split source modules (chat, routes,
memory, awareness, studio) and add build.sh so the binary can be rebuilt
without the studio’s concat trick. elb resolves the import graph and
emits one .c per .el; we link them together with cc. dist/soul-el now
points at dist/neuron via symlink (matching the launchctl plist).