How the agent is connected — determines its understanding of the file and command
execution environment.
Note: The defect CLI binary itself runs as an ACP server over stdio; all real paths
currently go through Frontend::Acp. Frontend::Cli and Frontend::Headless
are variants reserved for future forms (bare CLI user, server backend service).
Accessed via the ACP protocol (editor / IDE client).
fs_delegated / shell_delegated come from the ACP initialize handshake
negotiation:
true means file I/O / command execution is delegated to the client proxy,
false means
executed locally. The agent uses this to know whether it is facing a local
environment or a remote proxy.