Frame terminal canvas with chrome padding

MacApp/.swiftlint.yml

@@ -142,10 +142,10 @@ custom_rules:
     regex: '\bColor\.black\b'
     message: "Use DS.Color.* semantic tokens instead of Color.black."
     severity: error
-    # Wave 2 note: the `Relay` target remains excluded because AppRootView uses
-    # Color.black as the terminal canvas background fallback — the canvas is
-    # outside the design-system semantic palette and migrates in Wave 6
-    # alongside the terminal-specific theming pipeline.
+    # Relay target stays excluded until two further `Color.black` fallbacks
+    # in AppRootView (lines for the Welcome-transition canvas and the
+    # NoSessionPlaceholder backdrop) are replaced with theme-aware tokens.
+    # Tracked as a follow-up cleanup to the Wave 6 rollout.
     excluded:
       - "Packages/RemoteTerminal"
       - "Packages/TerminalSwiftTerm"

MacApp/Relay/AppRootView.swift

@@ -2,6 +2,7 @@ import AgentOrchestrator
 import ComposableArchitecture
 import DesignSystem
 import PaneManager
+import SharedModels
 import SwiftUI
 import TerminalFeature
 import UniformTypeIdentifiers
@@ -186,29 +187,36 @@ private struct AgentTerminalView: View {
     let registry: TerminalSessionRegistry
 
     @Environment(\.accessibilityReduceMotion) private var reduceMotion
+    @Environment(\.terminalTheme) private var terminalTheme
 
     var body: some View {
         VStack(spacing: 0) {
-            // Terminal view
-            if let sessionID = store.terminal.sessionID {
-                TerminalViewRepresentable(
-                    sessionID: sessionID,
-                    registry: registry,
-                    configuration: store.terminal.configuration,
-                    reduceMotion: reduceMotion
-                )
-                .frame(maxWidth: .infinity, maxHeight: .infinity)
-            } else {
-                // Terminal canvas background — see note above on `Color.black`.
-                Color.black
-                    .frame(maxWidth: .infinity, maxHeight: .infinity)
+            // Terminal canvas — framed inside rounded chrome so the content
+            // surface shows through around the edges. Connecting-state
+            // fallback mirrors the user's chosen terminal palette so there
+            // is no black flash before the palette is applied.
+            Group {
+                if let sessionID = store.terminal.sessionID {
+                    TerminalViewRepresentable(
+                        sessionID: sessionID,
+                        registry: registry,
+                        configuration: store.terminal.configuration,
+                        reduceMotion: reduceMotion
+                    )
+                } else {
+                    Color(nsColor: terminalTheme.background.nsColor)
+                }
             }
+            .frame(maxWidth: .infinity, maxHeight: .infinity)
+            .clipShape(.rect(cornerRadius: DS.Radius.sm, style: .continuous))
+            .padding(DS.Spacing.xs)
 
-            Divider()
-
-            // Status bar
+            // Status bar — no divider: colour contrast between the content
+            // surface chrome and the canvas beneath the chrome carries the
+            // separation.
             AgentStatusBarView(store: store)
         }
+        .background(DS.Color.surfaceContent)
     }
 }