refactor: add approval runtime sdk seam

src/plugin-sdk/approval-runtime.ts

@@ -0,0 +1,33 @@
+// Approval request/reply helpers for exec and plugin approval flows.
+
+export {
+  DEFAULT_EXEC_APPROVAL_TIMEOUT_MS,
+  type ExecApprovalDecision,
+  type ExecApprovalRequest,
+  type ExecApprovalRequestPayload,
+  type ExecApprovalResolved,
+  type ExecHost,
+} from "../infra/exec-approvals.js";
+export {
+  buildExecApprovalPendingReplyPayload,
+  getExecApprovalApproverDmNoticeText,
+  getExecApprovalReplyMetadata,
+  type ExecApprovalPendingReplyParams,
+  type ExecApprovalReplyDecision,
+  type ExecApprovalReplyMetadata,
+} from "../infra/exec-approval-reply.js";
+export { resolveExecApprovalCommandDisplay } from "../infra/exec-approval-command-display.js";
+export {
+  resolveExecApprovalSessionTarget,
+  type ExecApprovalSessionTarget,
+} from "../infra/exec-approval-session-target.js";
+export {
+  buildPluginApprovalExpiredMessage,
+  buildPluginApprovalRequestMessage,
+  buildPluginApprovalResolvedMessage,
+  DEFAULT_PLUGIN_APPROVAL_TIMEOUT_MS,
+  MAX_PLUGIN_APPROVAL_TIMEOUT_MS,
+  type PluginApprovalRequest,
+  type PluginApprovalRequestPayload,
+  type PluginApprovalResolved,
+} from "../infra/plugin-approvals.js";