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-224_mavlink_gcs_gateway.md

@@ -0,0 +1,84 @@
+# MAVLink GCS Gateway
+
+**Task**: AZ-224_mavlink_gcs_gateway
+**Name**: MAVLink GCS Gateway
+**Description**: Subscribe to FC telemetry, emit `GPS_INPUT`, and publish QGC-visible status/failsafe messages.
+**Complexity**: 3 points
+**Dependencies**: AZ-220_shared_runtime_contracts, AZ-222_runtime_config_errors_telemetry
+**Component**: MAVLink And GCS Integration
+**Tracker**: AZ-224
+**Epic**: AZ-210
+
+## Problem
+
+The runtime needs a strict protocol boundary for ArduPilot Plane telemetry in and GPS-denied estimates/status out.
+
+## Outcome
+
+- FC telemetry is normalized into shared samples.
+- `GPS_INPUT` is emitted only from validated position estimates.
+- QGC status is rate-limited and safety-relevant.
+
+## Scope
+
+### Included
+- Telemetry subscription behavior.
+- `GPS_INPUT` field validation and emission result.
+- QGC status/failsafe message emission.
+
+### Excluded
+- Safety policy and covariance calculation.
+- SITL test runner implementation.
+
+## Dependencies
+
+### Document Dependencies
+- `_docs/02_document/contracts/shared/runtime_contracts.md`
+- `_docs/02_document/contracts/shared/config_errors_telemetry.md`
+
+## Acceptance Criteria
+
+**AC-1: Telemetry sample emitted**
+Given a valid FC telemetry stream
+When the gateway subscribes
+Then normalized telemetry samples are available to consumers.
+
+**AC-2: Invalid GPS_INPUT is rejected**
+Given a malformed or unsafe position estimate
+When emission is requested
+Then no invalid `GPS_INPUT` packet is emitted.
+
+**AC-3: Operator status is rate-limited**
+Given repeated mode changes or warnings
+When status is emitted
+Then QGC-visible messages stay within the configured rate.
+
+## Non-Functional Requirements
+
+**Reliability**
+- Connection loss is surfaced to wrapper/FDR.
+
+## Unit Tests
+
+| AC Ref | What to Test | Required Outcome |
+|--------|--------------|------------------|
+| AC-1 | Telemetry normalization | Shared sample emitted |
+| AC-2 | Invalid fix type/accuracy | Emission rejected |
+| AC-3 | Status burst | Rate limit enforced |
+
+## Blackbox Tests
+
+| AC Ref | Initial Data/Conditions | What to Test | Expected Behavior | NFR References |
+|--------|-------------------------|--------------|-------------------|----------------|
+| AC-2 | Plane SITL | `GPS_INPUT` output | Fields match ArduPilot expectations | Reliability |
+
+## Constraints
+
+- v1 emits `GPS_INPUT` only.
+- Do not hide MAVLink disconnects or invalid output errors.
+
+## Risks & Mitigation
+
+**Risk 1: ArduPilot parameter mismatch**
+- *Risk*: Plane ignores or mishandles emitted estimates.
+- *Mitigation*: SITL validation remains a release gate.