feat: add ui.seamColor accent

apps/ios/Sources/Model/NodeAppModel.swift

@@ -22,6 +22,7 @@ final class NodeAppModel {
     var bridgeServerName: String?
     var bridgeRemoteAddress: String?
     var connectedBridgeID: String?
+    var seamColorHex: String?
 
     private let bridge = BridgeSession()
     private var bridgeTask: Task<Void, Never>?
@@ -225,6 +226,7 @@ final class NodeAppModel {
                                     self.bridgeRemoteAddress = addr
                                 }
                             }
+                            await self.refreshBrandingFromGateway()
                             await self.startVoiceWakeSync()
                             await self.showA2UIOnConnectIfNeeded()
                         },
@@ -264,6 +266,7 @@ final class NodeAppModel {
                 self.bridgeServerName = nil
                 self.bridgeRemoteAddress = nil
                 self.connectedBridgeID = nil
+                self.seamColorHex = nil
                 self.showLocalCanvasOnDisconnect()
             }
         }
@@ -279,9 +282,42 @@ final class NodeAppModel {
         self.bridgeServerName = nil
         self.bridgeRemoteAddress = nil
         self.connectedBridgeID = nil
+        self.seamColorHex = nil
         self.showLocalCanvasOnDisconnect()
     }
 
+    var seamColor: Color {
+        Self.color(fromHex: self.seamColorHex) ?? Self.defaultSeamColor
+    }
+
+    private static let defaultSeamColor = Color(red: 0.62, green: 0.88, blue: 1.0)
+
+    private static func color(fromHex raw: String?) -> Color? {
+        let trimmed = (raw ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmed.isEmpty else { return nil }
+        let hex = trimmed.hasPrefix("#") ? String(trimmed.dropFirst()) : trimmed
+        guard hex.count == 6, let value = Int(hex, radix: 16) else { return nil }
+        let r = Double((value >> 16) & 0xFF) / 255.0
+        let g = Double((value >> 8) & 0xFF) / 255.0
+        let b = Double(value & 0xFF) / 255.0
+        return Color(red: r, green: g, blue: b)
+    }
+
+    private func refreshBrandingFromGateway() async {
+        do {
+            let res = try await self.bridge.request(method: "config.get", paramsJSON: "{}", timeoutSeconds: 8)
+            guard let json = try JSONSerialization.jsonObject(with: res) as? [String: Any] else { return }
+            guard let config = json["config"] as? [String: Any] else { return }
+            let ui = config["ui"] as? [String: Any]
+            let raw = (ui?["seamColor"] as? String)?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
+            await MainActor.run {
+                self.seamColorHex = raw.isEmpty ? nil : raw
+            }
+        } catch {
+            // ignore
+        }
+    }
+
     func setGlobalWakeWords(_ words: [String]) async {
         let sanitized = VoiceWakePreferences.sanitizeTriggerWords(words)
 

apps/ios/Sources/RootCanvas.swift

@@ -147,7 +147,9 @@ private struct CanvasContent: View {
                     // Talk mode lives on a side bubble so it doesn't get buried in settings.
                     OverlayButton(
                         systemImage: self.appModel.talkMode.isEnabled ? "waveform.circle.fill" : "waveform.circle",
-                        brighten: self.brightenButtons)
+                        brighten: self.brightenButtons,
+                        tint: self.appModel.seamColor,
+                        isActive: self.appModel.talkMode.isEnabled)
                     {
                         let next = !self.appModel.talkMode.isEnabled
                         self.talkEnabled = next
@@ -251,13 +253,15 @@ private struct CanvasContent: View {
 private struct OverlayButton: View {
     let systemImage: String
     let brighten: Bool
+    var tint: Color? = nil
+    var isActive: Bool = false
     let action: () -> Void
 
     var body: some View {
         Button(action: self.action) {
             Image(systemName: self.systemImage)
                 .font(.system(size: 16, weight: .semibold))
-                .foregroundStyle(.primary)
+                .foregroundStyle(self.isActive ? (self.tint ?? .primary) : .primary)
                 .padding(10)
                 .background {
                     RoundedRectangle(cornerRadius: 12, style: .continuous)
@@ -275,9 +279,26 @@ private struct OverlayButton: View {
                                         endPoint: .bottomTrailing))
                                 .blendMode(.overlay)
                         }
+                        .overlay {
+                            if let tint {
+                                RoundedRectangle(cornerRadius: 12, style: .continuous)
+                                    .fill(
+                                        LinearGradient(
+                                            colors: [
+                                                tint.opacity(self.isActive ? 0.22 : 0.14),
+                                                tint.opacity(self.isActive ? 0.10 : 0.06),
+                                                .clear,
+                                            ],
+                                            startPoint: .topLeading,
+                                            endPoint: .bottomTrailing))
+                                    .blendMode(.overlay)
+                            }
+                        }
                         .overlay {
                             RoundedRectangle(cornerRadius: 12, style: .continuous)
-                                .strokeBorder(.white.opacity(self.brighten ? 0.24 : 0.18), lineWidth: 0.5)
+                                .strokeBorder(
+                                    (self.tint ?? .white).opacity(self.isActive ? 0.34 : (self.brighten ? 0.24 : 0.18)),
+                                    lineWidth: self.isActive ? 0.7 : 0.5)
                         }
                         .shadow(color: .black.opacity(0.35), radius: 12, y: 6)
                 }