Address review feedback:
- Move ErrSuspendForCheckpoint from checkpoint.go to errors.go
next to the rest of the agent error declarations; drop the
colon in the error string so it matches the existing
`agent run <event>` style used by the supervisor sentinels.
- Replace the inline `outerCtx := ctx; ctx = context.WithoutCancel(ctx)`
pattern with a small `suspendShield` helper in context.go used
by coreLoop, resumeWithOpts, and resumeNested. Reads more
cleanly and stops surfacing the WithoutCancel mechanism at
every call site.
- Trim the doc comments on Run, RunStreamed, Resume, Restore, the
ErrSuspendForCheckpoint declaration, and the saveCtx comment in
restoreNestedSuspended down to the contract bullet.
Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>
Introduce Checkpoint, CheckpointStore, SuspendedError, AgentRegistry,
and CompletedCall types. Add cooperative stop signal via context.
Export CompletedCall (was unexported completedCall) so checkpoints
can reference completed tool results. Add JSON tags to ToolResult
and ApprovalResult for checkpoint serialization.
Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>
