Fix linter issues in agent-run packages

Replace the single-case switch in the agent-run handler with an if,
and add the blank lines wsl_v5 requires around statements in the
approval checkpoint, worker tests, and policy-set registration.

Signed-off-by: Bryan Frimin <bryan@probo.com>

pkg/agent/approval.go

@@ -80,6 +80,7 @@ func MergeApprovalDecisions(
 	if cp.ApprovalInput == nil {
 		cp.ApprovalInput = make(map[string]ApprovalResult, len(decisions))
 	}
+
 	maps.Copy(cp.ApprovalInput, decisions)
 
 	data, err := json.Marshal(&cp)