refactor: normalize group session keys

apps/macos/Tests/ClawdisIPCTests/MenuSessionsInjectorTests.swift

@@ -29,6 +29,11 @@ struct MenuSessionsInjectorTests {
                 id: "main",
                 key: "main",
                 kind: .direct,
+                displayName: nil,
+                surface: nil,
+                subject: nil,
+                room: nil,
+                space: nil,
                 updatedAt: Date(),
                 sessionId: "s1",
                 thinkingLevel: "low",
@@ -38,9 +43,14 @@ struct MenuSessionsInjectorTests {
                 tokens: SessionTokenStats(input: 10, output: 20, total: 30, contextTokens: 200_000),
                 model: "claude-opus-4-5"),
             SessionRow(
-                id: "group:alpha",
-                key: "group:alpha",
+                id: "discord:group:alpha",
+                key: "discord:group:alpha",
                 kind: .group,
+                displayName: nil,
+                surface: nil,
+                subject: nil,
+                room: nil,
+                space: nil,
                 updatedAt: Date(timeIntervalSinceNow: -60),
                 sessionId: "s2",
                 thinkingLevel: "high",