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+# Handoff — Screens VNC app
+
+A snapshot of project state so another machine (or another Claude Code session) can pick up without any out-of-band context.
+
+## Resume on a new machine
+
+```sh
+# 1. Clone
+git clone git@gitea.treytartt.com:admin/Screens.git
+cd Screens
+
+# 2. Prerequisites (macOS host)
+brew install xcodegen            # reproducible .xcodeproj generation
+# Xcode 16+ required (Xcode 26 tested)
+
+# 3. Generate the Xcode project (not committed)
+xcodegen generate
+
+# 4. Open in Xcode (or build from CLI)
+open Screens.xcodeproj
+# - or -
+xcodebuild -scheme Screens -destination 'platform=iOS Simulator,name=iPhone 17' build
+
+# 5. Fast unit tests (no simulator)
+cd Packages/VNCCore && swift test    # ~0.4s, 3 tests
+cd ../VNCUI && swift test            # ~3s, 1 test
+```
+
+## Git layout
+
+- `main` — cumulative integrated history. Default branch.
+- `phase-N-<topic>` — per-phase branches; open a PR into `main` and merge.
+- Current branch in progress: **`phase-1-vnc-wiring`** (branched from `main` @ Phase 0 scaffold).
+
+## Phase status
+
+| Phase | Scope | Status |
+|-------|-------|--------|
+| 0 — Scaffold | Packages, app target, xcodegen, RoyalVNCKit dep, CI-compilable | ✅ merged to `main` (commit `2cff17f`) |
+| 1 — MVP connect/view/tap | Wire `VNCConnectionDelegate`, render framebuffer, touch input, Keychain auth | 🔄 in progress on `phase-1-vnc-wiring` |
+| 2 — Input parity | Trackpad mode, hardware keyboard, pointer, adaptive quality, reconnect | ⏳ not started |
+| 3 — Productivity | Clipboard sync, multi-monitor, Apple Pencil, screenshots, view-only, curtain mode | ⏳ not started |
+| 4 — Polish & ship | iPad multi-window, CloudKit sync, a11y, privacy manifest, TestFlight prep | ⏳ not started |
+
+Full plan: [docs/PLAN.md](./PLAN.md).
+
+## Critical architectural notes
+
+1. **RoyalVNCKit owns its own networking.** It constructs its own `NWConnection` internally from `VNCConnection.Settings`. Our `Transport` protocol in `VNCCore` is *not* on the RFB path — it's kept as the extension point for future SSH tunneling. Don't try to pipe bytes from `DirectTransport` into `VNCConnection`.
+
+2. **Delegate model.** `SessionController` should conform to `VNCConnectionDelegate` and bridge delegate callbacks (which arrive on internal RoyalVNCKit queues) to `@MainActor` state. Password supplied via `credentialFor:completion:` callback.
+
+3. **iOS framebuffer rendering is on us.** RoyalVNCKit ships macOS-only `VNCFramebufferView` (NSView). We render by grabbing `framebuffer.cgImage` and setting `FramebufferUIView.contentLayer.contents` on each `didUpdateFramebuffer` callback. IOSurface-backed path available for zero-copy later.
+
+4. **Swift 6 strict concurrency is on.** Cross-actor hops need care. Use `@MainActor` on everything UI-adjacent; mark Transport-style types as actors.
+
+5. **Name "Screens" is owned by Edovia.** Pick a different App Store title before any public artifact.
+
+## Dependencies
+
+| Package | Purpose | Version | License |
+|---------|---------|---------|---------|
+| [royalvnc](https://github.com/royalapplications/royalvnc) | RFB protocol, encodings, auth | `branch: main` (tagged releases blocked by transitive CryptoSwift unstable-version constraint) | MIT |
+| Apple first-party | Network, SwiftData, Security, UIKit, SwiftUI, Observation | iOS 18 SDK | — |
+
+## Build artifacts
+
+- `Screens.xcodeproj/` — **git-ignored**. Regenerate with `xcodegen generate`.
+- `Packages/*/.build/` — git-ignored. `swift build` or Xcode resolves.
+- `Packages/*/Package.resolved` — git-ignored; change if you want reproducible dep versions across machines (recommended for an app target — consider flipping later).
+
+## Files to look at first
+
+- `docs/PLAN.md` — full plan
+- `Project.yml` — xcodegen project definition
+- `Screens/App/AppStateController.swift` — app-level state machine
+- `Packages/VNCCore/Sources/VNCCore/Session/SessionController.swift` — the stub that Phase 1 will replace with a real `VNCConnectionDelegate` integration
+- `Packages/VNCUI/Sources/VNCUI/Session/FramebufferUIView.swift` — where incoming framebuffer `CGImage`s land
+
+## Open decisions
+
+- **App Store name** — not "Screens" (trademarked).
+- **Bundle identifier** — currently `com.example.screens` placeholder; set to your real prefix.
+- **Team ID / signing** — currently `CODE_SIGN_STYLE: Automatic`; point at your team for device builds.
+- **Privacy manifest** — scheduled for Phase 4; will enumerate `UIPasteboard`, `UserDefaults`, `NSPrivacyAccessedAPICategoryFileTimestamp` reasons.
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+# Plan: VNC Client App (Screens-style) — iPhone + iPad
+
+## Context
+
+The user wants to build a VNC remote-desktop app for iPhone and iPad modeled on [Screens by Edovia](https://www.edovia.com/en/screens/), which is the market leader in the category. Screens exposes a premium, polished VNC experience: Bonjour discovery, saved connections, local + SSH tunneled transport, Touch Mode / Trackpad Mode input, clipboard sync, multi-monitor, hardware keyboard + Apple Pencil, and (in the full product) a relay service and file transfer.
+
+Working directory `/Users/treyt/Desktop/code/Screens` is empty — this is a greenfield build. Scope agreed with the user:
+
+- **Platforms**: iPhone + iPad (iOS/iPadOS). No Mac / visionOS in phase 1.
+- **RFB engine**: [RoyalVNCKit](https://github.com/royalapplications/royalvnc) (MIT, Swift, supports Raw/CopyRect/RRE/CoRRE/Hextile/Zlib/ZRLE/Tight + VNC password + Apple Remote Desktop auth). iOS UIView rendering is flagged "work in progress" upstream, so we own the UIKit framebuffer view.
+- **MVP ambition**: "Feature-parity push" — MVP + clipboard sync, multi-monitor, trackpad mode, Apple Pencil. ~2 months.
+- **Remote access strategy**: Tailscale. A device on a tailnet is reached by its Tailscale IP or MagicDNS name exactly like a LAN host, and the transport is already WireGuard-encrypted end-to-end. The app does not need to bundle SSH tunneling or a relay — we just connect TCP and let Tailscale handle the network layer.
+- **No account system / subscription** in phase 1. Saved connections sync via CloudKit (iCloud) if the user opts in.
+
+Intended outcome: a shippable, App Store-quality VNC client that a Mac/Linux/RPi user can drive from an iPhone or iPad on their LAN or through SSH.
+
+## Architecture
+
+```
+┌──────────────────────────────────────────────────────────────┐
+│ App target (thin shell, ~10% of code)                        │
+│   VNCApp.swift · RootView · AppStateController               │
+└──────────────────────┬───────────────────────────────────────┘
+                       │ environment
+┌──────────────────────▼───────────────────────────────────────┐
+│ VNCUI (Swift package)                                        │
+│   ConnectionListView · AddConnectionView · SessionView       │
+│   FramebufferView (UIViewRepresentable → FramebufferUIView)  │
+│   InputMapper (Touch/Trackpad/HW keyboard/Pencil)            │
+└──────────────────────┬───────────────────────────────────────┘
+                       │
+┌──────────────────────▼───────────────────────────────────────┐
+│ VNCCore (Swift package, @testable without simulator)         │
+│   SessionController ◀─────── Transport protocol              │
+│        │                        └── DirectTransport (NW)     │
+│        ▼                                                      │
+│   RoyalVNCKit  ·  DiscoveryService (NWBrowser _rfb._tcp)     │
+│   ConnectionStore (SwiftData + Keychain refs)                │
+│   KeychainService · ClipboardBridge                          │
+└──────────────────────────────────────────────────────────────┘
+```
+
+`Transport` stays behind a protocol so a future relay or optional SSH-tunnel add-on can slot in without touching `SessionController`.
+
+### Why this shape
+
+- **Thin `@main`** and `AppStateController`: the app has distinct states (launching → list → connecting → connected → error). Modeling them as an enum avoids "boolean soup" and keeps logic testable. Pattern from the `axiom:axiom-app-composition` skill (Part 1).
+- **VNCCore is a Swift Package** with no UI imports. This lets us run the protocol + transport tests with `swift test` (~sub-second) instead of `xcodebuild test`. 60× faster TDD loop.
+- **Transport protocol** isolates the network layer from the session layer. Phase-1 has one implementation (`DirectTransport` over `NWConnection`), which already handles both LAN and Tailscale — a tailnet host resolves and routes like any other host from the app's perspective. If we ever add SSH tunneling or a rendezvous relay, they drop in as additional `Transport` conformers.
+- **UIKit-backed framebuffer view** wrapped in `UIViewRepresentable`. SwiftUI's `Canvas` is too slow for 30+ fps blits at ~2M pixels. A `CALayer` with `contents = IOSurface`-backed `CGImage` (or a small Metal view if ZRLE/Tight decode runs on GPU later) gives us consistent 60 Hz.
+
+## Key Dependencies
+
+| Package | Purpose | License |
+| --- | --- | --- |
+| [royalvnc](https://github.com/royalapplications/royalvnc) | RFB protocol, encodings, auth | MIT |
+| Apple first-party: `Network`, `SwiftData`, `CloudKit`, `Security` (Keychain), `UIKit`, `SwiftUI`, `Combine` | n/a | n/a |
+
+Tailscale requires no SDK integration — it runs as a system-wide VPN/Network Extension installed separately by the user. Once active, remote hosts are reachable by Tailscale IP or MagicDNS name from our plain `NWConnection`.
+
+Deployment target: **iOS 18.0**. Gets us `@Observable` macro, SwiftData stability fixes, and modern Network.framework APIs. Skip iOS 26-only features (Liquid Glass components) behind `if #available` gates so we don't block on Xcode 26 availability.
+
+## Data Model
+
+SwiftData models live in `VNCCore`:
+
+```swift
+@Model final class SavedConnection {
+    @Attribute(.unique) var id: UUID
+    var displayName: String
+    var host: String                 // hostname, IPv4, or IPv6
+    var port: Int                    // default 5900
+    var colorTag: ColorTag           // UI identification
+    var lastConnectedAt: Date?
+    var preferredEncodings: [String] // ordered, persisted for reconnect
+    var keychainTag: String          // opaque ref to VNC password entry
+    var quality: QualityPreset       // .adaptive / .high / .low
+    var viewOnly: Bool
+    var curtainMode: Bool
+}
+```
+
+VNC passwords go to Keychain (`kSecClassGenericPassword` with `kSecAttrAccessible = kSecAttrAccessibleWhenUnlockedThisDeviceOnly`). The `keychainTag` on the model is the account name — we never persist the secret in SwiftData. Optional CloudKit sync of `SavedConnection` (minus secrets) via SwiftData's CloudKit integration.
+
+## Phased Delivery
+
+### Phase 0 — Scaffold (~3 days)
+- Create Xcode project (working name — App Store name TBD to avoid trademark conflict; brainstorm candidates before public launch).
+- SPM packages `VNCCore` and `VNCUI` inside the repo.
+- Add RoyalVNCKit as a dependency.
+- Thin `@main`, `AppStateController` with `case launching / list / connecting(SavedConnection) / session(SessionController) / error(AppError)`, `RootView` switch.
+- CI via `xcodebuild test` on `VNCUI` + `swift test` on `VNCCore`.
+- App icon + launch screen placeholder.
+
+### Phase 1 — MVP connect + view + tap (~2 weeks)
+1. `DiscoveryService` using `NWBrowser` on `_rfb._tcp` and `_workstation._tcp` (macOS Screen Sharing advertises the latter).
+2. `ConnectionStore` — SwiftData CRUD + Keychain round-trip.
+3. `ConnectionListView`, `AddConnectionView`, basic Liquid Glass cards when available.
+4. `DirectTransport` using `NWConnection` (TCP, TLS optional for VeNCrypt later).
+5. `SessionController` wrapping `RoyalVNCKit.VNCConnection`: lifecycle, framebuffer updates, reconnection.
+6. `FramebufferUIView` (UIKit): `CALayer` whose `contents` is a `CGImage` built from the RoyalVNC framebuffer bytes. Handle partial rect updates (dirty-rect blits, not full redraws).
+7. Touch Mode input: tap → left click, two-finger tap → right click, pan → scroll. Nothing fancy yet.
+8. VNC password auth + "save to Keychain" flow.
+
+**Exit criterion**: from a cold launch I can discover my Mac via Bonjour, enter the Screen Sharing password, see the desktop, click a Finder icon, and type into Spotlight.
+
+### Phase 2 — Input parity (~1.5 weeks)
+- Trackpad Mode: a floating soft cursor SwiftUI overlay; pan moves the cursor, tap-to-click, pinch to zoom into the framebuffer. Momentum scroll.
+- Hardware keyboard via `pressesBegan`/`pressesEnded` on the framebuffer view — full modifier + function key support (⌘, ⌥, ⌃, ⇧, F1–F20, arrows).
+- Magic Trackpad 2 / Magic Mouse: `UIPointerInteraction` + indirect pointer events → VNC pointer events.
+- Adaptive quality: choose encoding (Tight vs ZRLE) and JPEG quality based on `NWPathMonitor` link type + measured RTT.
+- Reconnect backoff with jitter.
+
+### Phase 3 — Productivity features (~2 weeks)
+- Clipboard sync: bidirectional `UIPasteboard` ↔ VNC `ClientCutText`/`ServerCutText`. Handle Unicode (ISO-8859-1 limitation of classic spec — prefer extended clipboard pseudo-encoding where the server advertises it). Opt-in toggle per connection and a global kill switch for privacy.
+- Multi-monitor: parse `DesktopSize` / `ExtendedDesktopSize` pseudo-encodings; offer a monitor picker that sends `SetDesktopSize` or pans the viewport. Remember last selection per connection.
+- Apple Pencil: treat as pointer with pressure — if the remote is a Mac running a drawing app, pass pressure via a custom extension if available, otherwise plain pointer. Hover support on M2 iPad Pro.
+- Screenshot capture: grab current framebuffer bytes → `CGImage` → share sheet.
+- "On disconnect" actions: prompt / reconnect / return to list.
+- View Only and Curtain Mode toggles wired into RoyalVNC's session options.
+
+### Phase 4 — Polish + ship (~1.5 weeks)
+- iPad multi-window: `WindowGroup(for: SavedConnection.ID.self)` so each connection can open in its own window, each with its own `SessionController` instance.
+- CloudKit sync of `SavedConnection` records via SwiftData's `ModelConfiguration(cloudKitDatabase: .private("iCloud..."))`. Secrets stay local-Keychain only.
+- Accessibility pass (VoiceOver, Dynamic Type on non-framebuffer chrome, Reduce Motion).
+- Empty states, error recovery, network-change handling (Wi-Fi → cellular with session pause/resume).
+- Privacy manifest, App Store screenshots, TestFlight.
+
+## Critical Files to Create
+
+```
+Screens.xcodeproj
+Screens/
+  App/
+    VNCApp.swift                       # @main (thin)
+    RootView.swift
+    AppStateController.swift
+  Resources/
+    Assets.xcassets
+    Info.plist
+
+Packages/VNCCore/
+  Package.swift
+  Sources/VNCCore/
+    Session/
+      SessionController.swift          # wraps RoyalVNCKit.VNCConnection
+      SessionState.swift               # enum of connection states
+    Transport/
+      Transport.swift                  # protocol
+      DirectTransport.swift            # NWConnection
+      SSHTunnelTransport.swift         # SwiftNIOSSH
+    Discovery/
+      DiscoveryService.swift           # NWBrowser on _rfb._tcp + _workstation._tcp
+    Storage/
+      SavedConnection.swift            # @Model
+      ConnectionStore.swift            # actor-wrapped ModelContext helper
+    Security/
+      KeychainService.swift            # SecItem wrapper
+    Clipboard/
+      ClipboardBridge.swift
+  Tests/VNCCoreTests/
+    TransportTests.swift
+    SessionControllerTests.swift       # mock Transport
+    ConnectionStoreTests.swift
+
+Packages/VNCUI/
+  Package.swift
+  Sources/VNCUI/
+    List/
+      ConnectionListView.swift
+      ConnectionCard.swift
+    Edit/
+      AddConnectionView.swift
+    Session/
+      SessionView.swift                # hosts the framebuffer + toolbars
+      FramebufferView.swift            # UIViewRepresentable
+      FramebufferUIView.swift          # UIKit CALayer-backed renderer
+      InputMapper.swift                # touch/trackpad/keyboard → RFB events
+      TrackpadCursorOverlay.swift
+      ToolbarView.swift
+    Settings/
+      SettingsView.swift
+```
+
+## Reusable Pieces (don't rebuild)
+
+- **RoyalVNCKit** gives us the entire RFB state machine, encodings, auth. We *consume* it; we do not fork.
+- **`NWBrowser` + `NWListener`** from Network.framework — no need for third-party Bonjour.
+- **`AppStateController` pattern** from `axiom:axiom-app-composition` — copy the boilerplate for loading/list/session/error states.
+- **`axiom:axiom-swiftui-nav`** for the iPad split-view connection-list-to-session navigation.
+- **`axiom:axiom-uikit-bridging`** for `UIViewRepresentable` coordinator patterns on `FramebufferUIView`.
+- **`axiom:axiom-keychain`** for the `SecItem` wrapper.
+- **`axiom:axiom-networking`** for `NWConnection` TLS/retry patterns reused inside `DirectTransport`.
+
+## Verification
+
+Layered testing, unit-heavy because the simulator is slow.
+
+1. **VNCCore unit tests (`swift test`, ~sub-second)**
+   - `TransportTests`: feed a synthetic RFB handshake byte stream through a `MockTransport`, assert `SessionController` transitions.
+   - `ConnectionStoreTests`: in-memory SwiftData container, verify CRUD + Keychain round-trip (Keychain stubbed via protocol in tests).
+   - `DiscoveryServiceTests`: inject a fake `NWBrowser` surface, verify published result list.
+
+2. **VNCUI UI snapshot / interaction tests (`xcodebuild test`)**
+   - `InputMapperTests`: given a `CGPoint` in framebuffer coordinates and a gesture, assert the emitted RFB pointer/key events.
+   - Preview-driven manual checks for `ConnectionListView`, `AddConnectionView` on iPhone + iPad size classes.
+
+3. **End-to-end manual matrix** (run before TestFlight each phase):
+   - Mac (macOS Screen Sharing, port 5900) — discovery, password, Touch Mode click through, clipboard.
+   - Linux (`tigervnc-server` in Docker) — ZRLE encoding, resolution change during session.
+   - Raspberry Pi (`realvnc-vnc-server`) — Raspberry Pi Connect auth variant, low-bandwidth adaptive quality.
+   - Tailscale remote case: the same three above with the iPhone on cellular reaching the host by its MagicDNS name.
+   - iPad multi-window: two simultaneous sessions to different hosts.
+   - Cellular → Wi-Fi handoff mid-session (airplane-mode toggle).
+
+4. **Performance budget** — on iPhone 15, a 2560×1440 @ 30 fps ZRLE stream should stay under 25% CPU and 40% battery-per-hour. Profile with Instruments Time Profiler + Energy Log each phase. See `axiom:axiom-performance-profiling`.
+
+5. **App Review preflight**: privacy manifest for `NSUserDefaults`, `UIPasteboard`, and network access; screenshots per device class; `axiom:axiom-app-store-submission` checklist before first TestFlight.
+
+## Open Questions to Resolve Before Phase 0
+
+- **App Store name**: "Screens" is owned by Edovia — we cannot ship under that name. Pick a working title (e.g. "Pikelet", "Portal VNC", "Farcast") before public artifacts.
+- **Bundle identifier + team ID**: confirm Apple Developer account + agreed bundle prefix.
+- **App icon + brand direction**: can be deferred to Phase 5 but worth sketching early.
+
+## Sources
+
+- [Screens by Edovia — marketing site](https://www.edovia.com/en/screens/)
+- [RoyalVNCKit (royalapplications/royalvnc)](https://github.com/royalapplications/royalvnc)
+- [RFB protocol — Wikipedia](https://en.wikipedia.org/wiki/RFB_protocol) · [RFC 6143 (RFB 3.8)](https://datatracker.ietf.org/doc/html/rfc6143)
+- [Tailscale on iOS](https://tailscale.com/kb/1020/install-ios)
+- Axiom skills consulted: `axiom-app-composition`, `axiom-uikit-bridging`, `axiom-networking`, `axiom-keychain`, `axiom-swiftui-nav`, `axiom-performance-profiling`, `axiom-app-store-submission`.