docs: add Phase 3-4 SUMMARY files and update ROADMAP

Phase 3 (Lab 02 Network & VPC):
- 03-01-SUMMARY.md: Test infrastructure (7 test scripts, 1637 lines)
- 03-02-SUMMARY.md: Diátaxis documentation (11 files, 2500+ lines)
- 03-03-SUMMARY.md: Infrastructure implementation (VPC networks)

Phase 4 (Lab 03 Compute & EC2):
- 04-01-SUMMARY.md: Test infrastructure (7 test scripts, 1389 lines)
- 04-02-SUMMARY.md: Diátaxis documentation (11 files, 2500+ lines)
- 04-03-SUMMARY.md: Infrastructure implementation (EC2 simulation)

ROADMAP: Updated to reflect Phase 2-4 completion status

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.planning/phases/04-lab-03-compute-ec2/04-01-SUMMARY.md

@@ -0,0 +1,86 @@
+---
+gsd_summary_version: 1.0
+phase: 04-lab-03-compute-ec2
+plan: 01
+type: execute
+wave: 0
+completed_date: "2026-04-03"
+duration_seconds: 2400
+---
+
+# Phase 04 Plan 01: Test Infrastructure (TDD RED Phase) Summary
+
+**One-liner:** Created comprehensive test suite following TDD methodology for Lab 03 Compute & EC2, validating Docker resource limits (CPU/memory), healthcheck configuration, and INF-03 compliance.
+
+## Overview
+
+Plan 04-01 established the test infrastructure foundation for Lab 03 (Compute & EC2) following Test-Driven Infrastructure (TDI) principles. All tests were created in RED phase (failing initially since no implementation exists), enabling students to verify their work as they progress through resource limits and healthcheck implementation.
+
+## Artifacts Created
+
+| File | Lines | Purpose |
+|------|-------|---------|
+| `labs/lab-03-compute/tests/01-resource-limits-test.sh` | 215 | Validate Docker resource limits (cpus, mem_limit) |
+| `labs/lab-03-compute/tests/02-healthcheck-test.sh` | 255 | Verify healthcheck configuration and behavior |
+| `labs/lab-03-compute/tests/03-enforcement-test.sh` | 287 | Ensure INF-03 compliance: resource limits enforcement with docker stats |
+| `labs/lab-03-compute/tests/04-verify-infrastructure.sh` | 84 | Infrastructure verification script |
+| `labs/lab-03-compute/tests/99-final-verification.sh` | 331 | Student "double check" command for end-to-end validation |
+| `labs/lab-03-compute/tests/run-all-tests.sh` | 138 | Test suite orchestration with fail-fast behavior |
+| `labs/lab-03-compute/tests/quick-test.sh` | 79 | Quick validation for development |
+
+**Total:** 1,389 lines of bash test code
+
+## Technical Implementation
+
+### TDD Methodology Applied
+- **RED Phase:** Tests fail initially (expected - no infrastructure exists)
+- **GREEN Phase:** Ready for next plan (04-03) where implementation will make tests pass
+- **REFACTOR Phase:** Future optimization without breaking tests
+
+### Key Technical Decisions
+
+1. **Resource Limits Testing**
+   - Tests verify cpus and mem_limit in docker-compose.yml
+   - Validates that limits are enforced with docker stats
+   - Tests OOM scenarios and CPU throttling
+
+2. **Healthcheck Testing**
+   - Tests verify healthcheck configuration syntax
+   - Validates container health status transitions
+   - Tests dependency management with service_healthy
+
+3. **INF-03 Compliance Verification**
+   - Ensures ALL containers have resource limits
+   - Verifies no unlimited containers exist
+   - Tests enforcement with stress scenarios
+
+4. **Multi-Phase Testing**
+   - Phase 1: Resource limits validation
+   - Phase 2: Healthcheck verification
+   - Phase 3: Enforcement testing (INF-03)
+   - Phase 4: Infrastructure verification
+   - Final: End-to-end validation
+
+## Requirements Covered
+
+- **TEST-01:** Test scripts validate resource limits and healthchecks
+- **TEST-05:** Test harness can be executed with single command (`run-all-tests.sh`)
+- **INF-03:** All containers have resource limits (cpus, mem_limit)
+- **LAB-03:** Docker resource limits and healthchecks simulate EC2
+
+## Deviations from Plan
+
+None - all tests created successfully without deviations.
+
+## Next Phase Readiness
+
+Test infrastructure is complete and ready for:
+- Plan 04-02: Diátaxis documentation creation
+- Plan 04-03: Infrastructure implementation (GREEN phase)
+
+The test suite provides comprehensive validation for Docker resource limits and healthchecks, with clear parallels to EC2 instance types and ELB health checks.
+
+---
+*Phase: 04-lab-03-compute-ec2*
+*Plan: 01*
+*Completed: 2026-04-03*