Add integration tests for UpGraphAction.Run()

## Context

Follow-up from PR #7776 (exegraph) review - wbreza Pass 3, finding M2.

## Problem

The 462-line UpGraphAction.Run() orchestrator in internal/cmd/up_graph.go has no dedicated unit/integration tests. The underlying engine core has 54 tests, but the graph-building and lifecycle orchestration logic in up_graph.go is only exercised via functional/E2E tests.

## Acceptance Criteria

- [ ] Add integration tests for UpGraphAction.Run() using existing mock infrastructure (mockexec, mockinput, etc.)
- [ ] Cover key scenarios: single-layer provision + deploy, multi-layer provision, service dependencies (uses:), error propagation from provision/deploy steps
- [ ] Verify deploy progress tracker integration (callbacks fire correctly)

## Estimate

~2-3hr effort using existing mock patterns from deploy_test.go and provision_test.go.

## Related

- PR #7776 (exegraph engine)