Design constraints

These boundaries keep real-time conversation responsive while background capabilities remain replaceable.

Area	Constraint
Scheduling	Apply events in order; run model calls and executor tasks asynchronously.
State	Update runtime memory before generating a response. Provider history is not the source of truth.
Speech	Only FrontBrain speaks through Floor. Nova may interrupt its own playback, never the user.
Attention	Surrogate evaluates background suggestions; it is not another conversational agent.
Execution	Extend capabilities through manifests, adapters and controllers, not capability-specific branches in Runtime.
Authorization	The host owns approvals and project identity. Model output cannot grant permissions.
Context and evidence	Give models bounded context. Retrieved text and images remain untrusted evidence.
Isolation	Keep document knowledge, personal memory and live task state separate. The desktop renderer uses a sandbox and a narrow preload API.

New capabilities must respect these boundaries. General workflow languages, unrestricted memory retrieval, cross-executor transactions and simultaneous speaking roles are outside the current scope. Devices and executors never expand their own permissions.