dlt/faultline/unresolve

Unresolve Faultline error group $ARGUMENTS.

1. Call get_error_group with the id and show: exception_class, message, occurrence_count, last_seen_at, current status, resolved_at.
2. If status is already unresolved, stop and tell the user — nothing to do.
3. If status is ignored, mention that unresolving will move it back to active triage. Ask the user to confirm.
4. Ask the user to confirm before mutating.
5. On confirmation, call unresolve_error_group with id.
6. Report the new status — resolved_at should be cleared in the response.

Common reasons to unresolve: a regression brought the error back, or the group was resolved by mistake. If the user mentions a new occurrence, Faultline auto-reopens resolved groups when they reoccur (ErrorGroup.find_or_create_from_exception), so explicit unresolve is rarely needed for active errors — verify before mutating.

If the tool returns error: "Tool disabled: mcp_readonly is true", tell the user to set c.mcp_readonly = false in their Faultline initializer.