Fix #804: Stop pause/resume controllers from duplicating PAUSED/RESUMED events

[Banx17]

Overview

This PR fixes issue #804 by stopping the stream.controller.ts from creating synthetic PAUSED and RESUMED events in the database when a stream is paused or resumed. Previously, the controllers would persist these events with a placeholder transaction hash, which led to duplicate history rows when the real on-chain event was indexed by SorobanEventWorker. Now, the state updates are fully delegated to the indexer, ensuring exactly one source of truth.

Related Issue

Closes #804

Changes

• stream.controller.ts: Removed prisma.stream.update and prisma.streamEvent.create in pauseStream and resumeStream handlers.
• tests: Added pause-resume.regression.test.ts to assert that pauseStream controller no longer modifies the DB, and exactly one PAUSED row is created by the indexer.
• tests: Updated integration tests in stream-actions.test.ts to reflect the removed database mutation expectations.

Verification

npm run lint ✅ completed (existing repo warnings only)
npm run typecheck ✅ passed
npm test -- tests/integration/pause-resume.regression.test.ts ✅ passed
npm run build ✅ passed