pub fn observer_for_config(config: &Config) -> Option<Arc<CheckpointObserver>>Expand description
Build the CheckpointObserver a fresh crate::Agent should install,
given a resolved crate::Config — called once, from
crate::agent::build_tool_context. Config::checkpoint_enabled is the
ONE gate: false (the default) returns None WITHOUT touching the
filesystem at all (no CheckpointStore::open, no directory created) —
the default-off byte-identity guarantee. true opens (creating if
needed) the shadow store at Config::checkpoint_dir, or
default_shadow_root when that’s unset; an I/O failure (unwritable
state dir) is reported via a one-time eprintln! warning and returns
None — graceful degrade, never a crash, never a blocked Agent::new.