Direction (your call): ride the existing chat (EasyUI) message + SSE pipeline,
synthesizing the app config from the Agent Soul rather than inventing a new
pipeline.
``AgentAppConfigManager`` shapes the Agent Soul (model + system prompt) plus any
app-level feature flags stored on ``app_model_config`` (Q3) into an
app_model_config-style dict, then reuses the same chat sub-managers
(ModelConfigManager / PromptTemplateConfigManager / features) to build an
EasyUI-shaped ``AgentAppConfig``. Model + prompt always come from the Soul
(single source of truth); feature flags from app_model_config when present.
Tests: 3 config-synthesis cases (soul model/prompt, feature-flag passthrough +
soul override, missing-model). ruff clean.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>