## Why

The Phase 3C gateway candidate has deterministic transport and scheduler tests
but no executable artifact generator for the normative ten-minute media
measurements and six bounded impairment profiles. Without that evidence,
P3C-029 through P3C-033 cannot be frozen truthfully.

## What Changes

- Add one stdlib-only qualification command for the three fixed encoded-media
  profiles and the exact six Section 7.2 impairment profiles.
- Emit bounded machine-readable configuration, raw observations, summaries,
  environment, topology, direction, queue discipline, and tool version.
- Fail the command when payload integrity, the 5 ms processing p95, impairment
  bounds, fairness, capacity-step convergence, or aggregate cap gates fail.
- Keep live Apollo, macOS, physical firewall, real encoder fidelity, and real
  multi-host scale explicitly deferred-owner-e2e.

## Capabilities

### New Capabilities

- `gateway-qualification`: Deterministic P3C-029 through P3C-033 media,
  processing, fairness, cap, and impairment evidence generation.

### Modified Capabilities

None.

## Impact

The Data Plane gains a qualification-only Go command, focused tests, and
documented evidence output. It adds no dependency, production transport
abstraction, provider route, codec operation, cgo, sidecar, or Connection
Server code.