Backend: Add “support tools” endpoints for safe borrower lookup and troubleshooting (read-only)

[greatest0fallt1me]

Description

Create read-only support endpoints to lookup borrower state (credit line snapshot, recent txs, reconciliation status) with strict RBAC. This reduces ad-hoc DB queries and improves incident response speed.

Requirements and context

• Must be secure, tested, and documented.
• Must be read-only and heavily access-controlled.

Suggested execution

git checkout -b feature/support-tools-readonly

Implement changes

• Add admin/support-only routes and schemas.
• Tests for RBAC boundaries and redaction.
• Update OpenAPI and docs.

Test and commit

npm test

Example commit message

feat(admin): support tools read-only troubleshooting endpoints

Guidelines

• Timeframe: 96 hours.