fix(render): stream long low-memory captures

[miguel-heygen]

What

Keep single-worker video renders on streaming encode in low-memory mode even when their duration exceeds the normal streaming cap.

Why

A 411-second render on an 8GB Windows host silently switched to disk capture because of the 240-second cap, then Chrome OOM-crashed at 56%. Raising the cap and bounding the frame data-URI cache completed the render. Low-memory mode should prefer bounded streaming memory over accumulating the full capture.

How

Teach shouldUseStreamingEncode to bypass only the duration clamp when lowMemoryMode is active. Format, validity, enablement, and worker-count gates remain unchanged.

Test plan

• bunx vitest run packages/producer/src/services/renderOrchestrator.test.ts -t shouldUseStreamingEncode
• bun run --filter @hyperframes/producer typecheck
• pre-commit lint, format, tracked-artifact, fallow, and typecheck hooks