## Why

Phase 3C has frozen the gateway and Connection Server image-engineering baseline, so the first
native VerseVDI endpoint can now be built against an immutable gateway-only authority model.
Phase 3D must add the user-facing macOS workspace, exact display negotiation, safe native
input, and streaming core without exposing Apollo/provider details or weakening the existing
control and transport boundaries.

## What Changes

- Build the Apple-Silicon SwiftUI/AppKit client and platform-neutral Rust Streaming Core
  behind one sized/versioned C ABI (`P3D-001`–`P3D-031`).
- Implement the reviewed native All/Favorites/Desktops/Pools workspace, bounded adaptive
  `300...360 pt` `16:10` preview cards with `16 pt` spacing and natural columns, search/sort,
  a Connections menu, Settings through the app menu in a separate regular window,
  accessibility, and privacy-bounded desktop previews (`P3D-032`, `P3D-037`). Screenshot
  pixels are behavioral evidence, not authoritative geometry constants.
- Add feature-gated requested/effective display modes, Server-owned policy clamping,
  client display detection/disclosure, and explicit reconnect-on-display-change behavior
  (`P3D-033`–`P3D-034`).
- Add provider-neutral absolute pointer and high-resolution scroll input while preserving
  relative input, release-all, reserved local escape chords, letterbox exclusion, and scoped
  keyboard mapping (`P3D-035`–`P3D-036`).
- Keep authentication, manifests, media, input, and clipboard on the authenticated
  gateway-only route. The client receives no provider endpoint, provider credential, or
  Windows credential outside normal encrypted input.
- Defer remote apps, manual PC/direct-provider connections, live display renegotiation,
  multi-monitor remote topology, HDR, microphone, file/folder redirection, image clipboard,
  macros, Intel, public release, and provider-specific client UI.

## Capabilities

### New Capabilities

- `macos-native-foundation`: Platform baseline, Swift/Rust/C ABI ownership, authentication,
  resource/broker authority, gateway-only manifest validation, and fake-core-first delivery.
- `macos-media-presentation`: Registered media dispatch, hardware video presentation, audio,
  bounded queues, and observable quality without media persistence.
- `macos-input-control`: Provider-neutral keyboard, pointer, scroll, controller, text
  clipboard, mappings, reserved local chords, and release-all behavior.
- `macos-lifecycle-quality`: Interruption, reconnect, accessibility, privacy, diagnostics,
  packaging, rollback, uninstall, and candidate qualification behavior.
- `macos-workspace`: Screenshot-backed workspace/card interactions, All/Favorites/Desktops/
  Pools navigation, separate Settings and Connections command surfaces, search/sort, and
  privacy-bounded previews.
- `session-display-mode`: Feature-gated requested/effective display mode, Server policy
  clamping, client detection/disclosure, and owner Apollo IDD acceptance.

### Modified Capabilities

None. Existing Phase 3C gateway capabilities remain unchanged; this change consumes and
extends their separately owned Protocol surfaces without redefining their requirements.

## Impact

- **Protocol repository:** additive strict JSON display objects, feature identifiers, VGI1
  absolute/scroll grammar, cross-language bindings, fixtures, and compatibility tests.
- **Connection Server:** additive broker-session migration/query fields, request identity,
  allocation transaction/clamp, manifest disclosure, and provider-work projection.
- **Data Plane:** Protocol pin update, Go gateway input validation/Apollo translation, Rust
  core/C ABI/XCFramework, SwiftUI/AppKit client, tests, documentation, and private build
  configuration.
- **Provenance and license boundary:** Apollo, Moonlight, Microsoft Windows App, and Omnissa
  material remains reference evidence only. No proprietary Server or Planning content is
  copied into the GPLv3 Data Plane.
- **Hard stops:** unknown provider packet semantics, incompatible legacy response behavior,
  direct-provider routing, secret/media/input persistence, unsupported platform safety, or
  a failed deterministic gate blocks the affected capability. Live Apollo/macOS/firewall
  interoperability remains `deferred-owner-e2e` until the owner runs the frozen candidate.