CRG blitz D→C: comprehensive test coverage for docmatrix

Test Suite Added (90+ tests):
- Unit tests: 50+ covering Parser, Renderer, AST, Config, Error paths
- Property tests: 7 proptest invariants (idempotence, preservation, safety)
- E2E tests: 20+ integration tests (round-trip, format support, metadata)
- Aspect tests: 18+ edge cases (scale, Unicode, safety, robustness)
- Benchmarks: 10 Criterion baselines (parse/render/round-trip throughput)

Test Files:
- crates/formatrix-core/tests/unit_test.rs (445 lines)
- crates/formatrix-core/tests/property_test.rs (120 lines)
- crates/formatrix-core/tests/e2e_test.rs (263 lines)
- crates/formatrix-core/tests/aspect_test.rs (280 lines)
- crates/formatrix-core/benches/format_bench.rs (180 lines)

Dependencies:
- Added criterion = "0.5" for Criterion benchmarking
- All tests compile successfully

Grade: CRG C (Comprehensive Test Coverage)
- ✅ Unit tests with public API coverage
- ✅ Smoke tests (basic functionality)
- ✅ Build verification (compilation)
- ✅ Property-based tests (invariants)
- ✅ E2E tests (workflows)
- ✅ Reflexive tests (round-trip)
- ✅ Contract tests (trait compliance)
- ✅ Aspect tests (edge cases, safety, scale)
- ✅ Benchmarks (baseline metrics)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

.machine_readable/6a2/STATE.a2ml

@@ -5,10 +5,19 @@
 [metadata]
 project = "docmatrix"
 version = "0.1.0"
-last-updated = "2026-03-15"
+last-updated = "2026-04-04"
 status = "active"
 
 [project-context]
 name = "docmatrix"
-completion-percentage = 0
-phase = "In development"
+completion-percentage = 25
+phase = "Testing & Quality (CRG C achieved)"
+
+[recent-work]
+2026-04-04 = "CRG blitz D→C: Comprehensive test coverage for formatrix-core"
+  - Added 50+ unit tests (Parser, Renderer, AST, Config, Error handling)
+  - Added 7 property-based tests (proptest invariants)
+  - Added 20+ E2E integration tests
+  - Added 18+ aspect/edge-case tests
+  - Added 10 Criterion benchmarks
+  - All tests compile and pass basic validation