Refactor documentation to replace the Validation Harness with a separate E2E Test Suite, updating references throughout various documents. Adjust the autodev state to reflect the transition from the Decompose phase to the Implement phase, and revise the architecture documentation to clarify system boundaries and component relationships. Enhance risk mitigation documentation to specify affected components and update the component overview diagram accordingly.

_docs/02_tasks/todo/AZ-220_shared_runtime_contracts.md

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+# Shared Runtime Contracts
+
+**Task**: AZ-220_shared_runtime_contracts
+**Name**: Shared Runtime Contracts
+**Description**: Define the shared DTO and event contract surface used across the onboard runtime.
+**Complexity**: 3 points
+**Dependencies**: AZ-219_initial_structure
+**Component**: Bootstrap / Shared Contracts
+**Tracker**: AZ-220
+**Epic**: AZ-206
+
+## Problem
+
+Runtime components need common shapes for frames, telemetry, VIO state, position estimates, candidates, anchors, cache tiles, and FDR events.
+
+## Outcome
+
+- Components consume one documented shared contract surface.
+- Cross-component DTO drift is prevented before implementation begins.
+
+## Scope
+
+### Included
+- Shared runtime DTO names, fields, invariants, versioning rules, and contract tests.
+- Public contract document for consumers.
+
+### Excluded
+- Component-specific algorithms.
+- E2E runner-only report schemas.
+
+## Acceptance Criteria
+
+**AC-1: Shared contract exists**
+Given runtime components need common DTOs
+When the shared contracts are implemented
+Then each runtime component can import or reference the same contract surface.
+
+**AC-2: Contract validation exists**
+Given a malformed shared DTO
+When validation runs
+Then the input is rejected with a structured error.
+
+## Non-Functional Requirements
+
+**Compatibility**
+- Contract changes follow documented versioning rules.
+
+**Reliability**
+- Invalid or missing required fields are not silently ignored.
+
+## Unit Tests
+
+| AC Ref | What to Test | Required Outcome |
+|--------|--------------|------------------|
+| AC-1 | DTO construction for valid minimal values | Accepted |
+| AC-2 | Missing required timestamp or ID | Rejected with structured error |
+
+## Blackbox Tests
+
+| AC Ref | Initial Data/Conditions | What to Test | Expected Behavior | NFR References |
+|--------|-------------------------|--------------|-------------------|----------------|
+| AC-1 | Runtime started with contract consumers | Public interfaces exchange typed records | No component-specific duplicate shape required | Compatibility |
+
+## Constraints
+
+- Contracts are shared API surface and must be consumed through documented public modules.
+- Raw frame payloads are referenced, not retained in shared DTOs.
+
+## Risks & Mitigation
+
+**Risk 1: Contract drift**
+- *Risk*: Consumers create local incompatible DTOs.
+- *Mitigation*: Contract file is required dependency for consuming tasks.
+
+## Contract
+
+This task produces/implements the contract at `_docs/02_document/contracts/shared/runtime_contracts.md`.
+Consumers MUST read that file — not this task spec — to discover the interface.