## MODIFIED Requirements

### Requirement: Authenticated network synchronization feeds the device pool
The system SHALL expose an authenticated Host Agent operation that validates a host device snapshot against its authentication mode and durable device enrollments before delegating it to the existing device-pool synchronization behavior.

#### Scenario: Valid managed remote snapshot
- **WHEN** an authenticated enrollment-managed Host submits a complete snapshot containing only non-revoked device IDs enrolled to that Host with matching driver types
- **THEN** the device pool refreshes that Host and its devices with the same replacement and staleness semantics as an in-process synchronization call

#### Scenario: Valid legacy remote snapshot
- **WHEN** an authenticated statically configured Host submits a valid complete snapshot
- **THEN** the device pool preserves the existing compatible synchronization and ownership-conflict behavior

#### Scenario: Invalid snapshot is rejected atomically
- **WHEN** a Host Agent snapshot contains invalid identifiers, unowned cloud device IDs, conflicting driver metadata, statuses, or capability tags
- **THEN** the control plane rejects the snapshot without partially replacing the Host's previous pooled devices or heartbeat timestamp

## ADDED Requirements

### Requirement: Durable device enrollment identity is independent of pool presence
The cloud repository SHALL retain a Host-scoped device enrollment and its assigned `device_id` independently of whether the device appears in the Host's latest heartbeat snapshot.

#### Scenario: Enrolled device disconnects
- **WHEN** a Host submits a heartbeat that no longer includes a previously enrolled device
- **THEN** the pooled-device projection removes that device while its durable enrollment remains available for later idempotent re-enrollment

#### Scenario: Enrolled device reconnects
- **WHEN** the Host later enrolls or reports the same local device reference again
- **THEN** the control plane reuses the existing cloud `device_id`

### Requirement: Managed device identity cannot be claimed by another Host
The device pool SHALL derive managed device ownership from durable enrollment rather than accepting a caller-selected cloud device ID.

#### Scenario: Host reports another Host's managed device
- **WHEN** Host B includes a cloud device ID enrolled to Host A in its heartbeat
- **THEN** the control plane rejects Host B's snapshot and Host A retains ownership

#### Scenario: Prior Host becomes stale
- **WHEN** Host A becomes stale and Host B presents Host A's cloud device ID
- **THEN** the control plane still rejects implicit takeover because managed device transfer requires a future explicit operation