[Init] Initial commit - NetMesh terminal manager

domain/systemManager/resolveSystemSession.ts

@@ -0,0 +1,21 @@
+import { collectSessionIds } from '../workspace';
+import type { TerminalSession, Workspace } from '../../types';
+
+/** Resolve which terminal session the system sidebar should target (workspace focus-aware). */
+export function resolveSystemSidebarSession(
+  sessions: TerminalSession[],
+  activeWorkspace: Workspace | undefined,
+  focusedSessionId: string | undefined,
+  activeSession: TerminalSession | undefined,
+): TerminalSession | null {
+  if (activeWorkspace) {
+    const workspaceSessionIds = collectSessionIds(activeWorkspace.root);
+    const idSet = new Set(workspaceSessionIds);
+    const preferredId = focusedSessionId && idSet.has(focusedSessionId)
+      ? focusedSessionId
+      : workspaceSessionIds.find((id) => sessions.some((session) => session.id === id));
+    if (!preferredId) return null;
+    return sessions.find((session) => session.id === preferredId) ?? null;
+  }
+  return activeSession ?? null;
+}