VerseVDI-Data-Plane/openspec/changes/phase3c-gateway-audit-remediation/design.md

Context

The implementation already contains a source-shaped Apollo fake, native recovery, bounded gateway queues, fair pacing, Verse framing/QUIC, independent client support, lifecycle reporters, and low-cardinality telemetry. Audit defects arise where those existing pieces are bypassed or not connected.

Goals / Non-Goals

Goals:

• Reuse the existing production path for policy, lifecycle, recovery, telemetry, and qualification.
• Delete duplicate qualification simulation.
• Preserve all trust, cleanup, and resource bounds.

Non-Goals:

• Add codecs, provider transports, dependencies, or a generic lifecycle/telemetry framework.
• Claim live Apollo/macOS/firewall interoperability.
• Run the normative qualification before immutable consumer resolution.

Decisions

• Format ANNOUNCE from ProviderStreamPolicy using the pinned Moonlight common-c bitrate and codec attributes. H.264 and HEVC with audio enabled are supported; AV1 and audio disabled fail before management/network readiness.
• Treat the current exact client_decode string as the negotiated decode profile. The default advertises the bounded H.264+HEVC set, and provider work must be a member of it.
• Consume existing provider events in the gateway session loop. Termination and disconnect cancel forwarding, then reuse current cleanup/release/reporting machinery and its cleanup-pending result.
• On a full audio FEC map, evict the oldest block according to existing block ordering and increment existing drop telemetry.
• Sample existing process counters at heartbeat time; calculate rate from byte and monotonic-time deltas while leaving configured capacity in registration.
• Build qualification on the existing native/provider fixture and public QUIC client path. Production stage observations replace the standalone codec and arithmetic impairment simulator; short smoke gates freeze the wiring, while normative durations remain deferred.
• Preserve the production fair-pacer schedule across short host-timer overshoots so measured allocation can catch up within the already bounded provider queue instead of accumulating timer granularity as lost capacity.

Risks / Trade-offs

• [Apollo cannot represent disabled audio truthfully] → Reject it rather than silently streaming stereo.
• [Provider event races with media] → Cancel the session first and let bounded cleanup serialize final release/reporting.
• [Counter reset or zero elapsed time] → Emit zero measured rate and establish a new baseline.
• [Corrected qualification is more expensive] → Run only short smoke tests until the immutable candidate is frozen.
• [Pacer catch-up can emit a short burst after timer overshoot] → Clamp schedule debt to five milliseconds in addition to the existing 16-packet provider queue.

Migration Plan

Land focused red/green repairs locally, verify through the temporary Protocol workspace, preserve old artifacts as superseded, and stop at the publication boundary. After a separately authorized immutable Protocol release is pinned, freeze inputs and run the corrected normative qualification once.

Open Questions

None.