feat: add parallel agents configuration for 5 simultaneous deployments

New agent prompts:
- prompts/agent-3-documentation.md: Phase 3 documentation (K8s, agents, cloud)
  - Kubernetes usage guide
  - Advanced agents guide (9 agents)
  - Cloud integration guide
  - Quick reference card

Parallel execution matrix:
- PARALLEL-AGENTS-MATRIX.md: Comprehensive parallelism analysis
  - 5 agents can run simultaneously
  - Only 1 minor conflict (Agent 1 & 2 in internal/web/server.go)
  - Complete conflict analysis matrix
  - Merge strategy and timeline projection
  - Agent 4 & 5 specs (cloud tests, compliance frameworks)

Updated deployment guide:
- CLOUD-AGENTS-READY.md: Updated for 5-agent parallel execution

Agent assignments:
1. Agent 1: Event Streaming (high priority, 3-5 days)
2. Agent 2: REST API (high priority, 4-6 days)
3. Agent 3: Documentation (medium priority, 2-3 days)
4. Agent 4: Cloud Integration Tests (medium priority, 3-4 days)
5. Agent 5: Extended Compliance (low priority, 3-4 days)

Conflict analysis:
- Agent 1 & 2: Minor conflict in internal/web/server.go (easy merge)
- Agent 3, 4, 5: ZERO conflicts (completely separate files)

Timeline: 2 weeks to Phase 3 completion (60% → 100%)