contextual_request invokes run_contextual_stream, enriches memory context,
and forwards v3 stream frames via StreamFormatter (matching home/floating
request pattern). Episode stored after response.
contextual_scope_update appends a synthetic system message to the session
buffer (no LLM call) and returns contextual_scope_ack.
get_session_buffer module-level helper defined so tests can monkeypatch it.
WsFrameType enum extended with contextual_request, contextual_scope_update,
contextual_scope_ack (v8 frame types).
NOTE: test_contextual_ws.py fails locally due to missing litellm dependency
in this dev environment; passes in the full Docker stack.
Convert app/schemas.py → app/schemas/__init__.py so the contextual
module can live at app/schemas/contextual.py while keeping all existing
'from app.schemas import ...' calls unchanged.
ContextualScope mirrors the renderer's camelCase payload via
alias_generator=to_camel. render_scope_block produces a single-paragraph
human-readable summary injected into the contextual agent system prompt.
4 tests, all passing.
