feat(ios): W3 UI layer + integration CI + ntfy docs

T-iOS-11: TerminalScreen/KeyBar/TerminalViewModel + KeyByteMap (byte-for-byte keybar.ts, arrows excluded from UIKeyCommand to preserve DECCKM)
T-iOS-12: PairingScreen/VM — confirm-before-network (zero-call assertions), §5.4 four-tier warnings, Host construction per contract ruling
T-iOS-13: SessionListScreen/VM — Tunables-paced polling with leak-free teardown, optimistic kill+rollback, pending via overlay (LiveSessionInfo has no pending field)
T-iOS-14: GateBanner/PlanGateSheet/AwayDigestView/GateViewModel — three-way mapping from SessionCore Affordance single source, tap-epoch guard, per-epoch haptics
T-iOS-16: IntegrationTests vs real Node server (10 tests: origin guards, mirror, kill-close vs exit-frame differential, 16MiB+ESC/C0 replay) + ios.yml own-sources coverage gate (red-once demoed)
T-iOS-17: ios/README.md ntfy chapter (read-only verification, file:line cites)
Verified: 224 unit + 10 integration tests green; 5/5 semantic spot-checks; zero Owns violations

ios/Packages/SessionCore/Sources/SessionCore/KeyByteMap.swift

@@ -0,0 +1,57 @@
+/// Key-name → terminal byte-string table (T-iOS-11; pure data, no I/O).
+///
+/// Byte-for-byte mirror of the web client's `public/keybar.ts` `KEY_MAP` —
+/// the SINGLE source of truth for every label→bytes lookup on iOS: the KeyBar
+/// buttons AND the hardware `UIKeyCommand` mapping both resolve through here
+/// (plan §7 T-iOS-11). Hand-writing an escape sequence anywhere in the App
+/// layer is a review finding.
+///
+/// Gotcha carried over from the web client: Enter is `\r` (0x0D, carriage
+/// return), NOT `\n` — synthesized input with a linefeed breaks TUIs.
+public enum KeyByteMap {
+    /// One key the bar/hardware mapping can send. Raw values mirror the web
+    /// `KEY_MAP` property names; declaration order mirrors the web table.
+    public enum Key: String, Sendable, CaseIterable {
+        case esc
+        case escEsc
+        case shiftTab
+        case arrowUp
+        case arrowDown
+        case arrowLeft
+        case arrowRight
+        case enter
+        case ctrlC
+        case ctrlR
+        case ctrlO
+        case ctrlL
+        case ctrlT
+        case ctrlB
+        case ctrlD
+        case tab
+        case slash
+    }
+
+    /// The exact byte string to send as `ClientMessage.input(data:)` for `key`.
+    /// Values are verbatim from public/keybar.ts KEY_MAP (see file doc).
+    public static func bytes(for key: Key) -> String {
+        switch key {
+        case .esc: return "\u{1B}"
+        case .escEsc: return "\u{1B}\u{1B}"
+        case .shiftTab: return "\u{1B}[Z"
+        case .arrowUp: return "\u{1B}[A"
+        case .arrowDown: return "\u{1B}[B"
+        case .arrowLeft: return "\u{1B}[D"
+        case .arrowRight: return "\u{1B}[C"
+        case .enter: return "\r" // NOT "\n" (CLAUDE.md gotcha)
+        case .ctrlC: return "\u{03}"
+        case .ctrlR: return "\u{12}"
+        case .ctrlO: return "\u{0F}"
+        case .ctrlL: return "\u{0C}"
+        case .ctrlT: return "\u{14}"
+        case .ctrlB: return "\u{02}"
+        case .ctrlD: return "\u{04}"
+        case .tab: return "\t"
+        case .slash: return "/"
+        }
+    }
+}