[test] End-to-end test approval-node flows (expense/content/procurement) #47

Record-change flows are verified at runtime, but approval-node flows were not exercised end-to-end (the node suspends pending a decision):

• expense expense_approval (manager → ≥$1k finance-director tier)
• content publish_approval
• procurement pr_approval_required

Ask: find the approval decision API/UI, drive approve + reject paths, and assert the resulting status transitions + notifications. Add to the regression suite.

Follow-up from the 9-template optimization + 9.5.1 runtime-testing pass. Platform-level gaps are tracked separately in objectstack-ai/framework (#1867–#1877).