Fix and document Spaces hardware, config, and dev mode (#2318)
- spaces-gpus.md: Fix A10G small RAM (14 GB → 15 GB); mark H100 as removed; add Replicas and Streaming Logs/Events/Metrics sections
- spaces-config-reference.md: Add L40S hardware flavors (l40sx1, l40sx4, l40sx8); remove nonexistent TPU entries (v5e-*)
- spaces-dev-mode.md: Document programmatic Dev Mode API toggle
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
