PR-002.5: Application Layer — Command/Result pattern, end-to-end flow

- 8 commands (CreateFieldSession, CreateMission, RegisterArtifact,
  CreateObservation, CreateDecisionCase, ApproveDecision, StartReview,
  CompleteReview)
- 4 handlers with validation and orchestration
- Result<T, E> pattern — explicit success/failure, no exceptions
- End-to-end test: Session → Mission → DecisionCase → Approval
- 3 tests proving full flow works in memory
- ADR-007: Command/Result Pattern

Acceptance Criteria:
✅ CreateFieldSession → CreateMission → CreateDecisionCase → ApproveDecision
✅ Without PostgreSQL, Redis, S3, API, HTTP, UI
✅ Business logic verified before infrastructure attached

Next: PR-003 — PostgreSQL adapters (swap InMemory → Postgres)

packages/application/src/index.ts

@@ -0,0 +1,19 @@
+/**
+ * @landvex/application
+ *
+ * Application layer — orchestrates domain operations.
+ *
+ * Architecture:
+ * UI → Application Layer (commands/handlers) → Domain → Repository Interfaces → Adapters
+ *
+ * No business logic here. Only orchestration.
+ */
+
+// Commands
+export * from './commands/commands';
+
+// Results
+export * from './results/results';
+
+// Handlers
+export * from './handlers';