fix: group tree view by process name instead of PID

platforms/macos/Sources/Models/ProcessGroup.swift

@@ -14,12 +14,15 @@ import Foundation
 /// their owning process. This provides a hierarchical view where users can
 /// expand/collapse processes to see all their associated ports.
 struct ProcessGroup: Identifiable, Sendable {
-    /// Process ID (PID) - used as stable identifier
-    let id: Int
+    /// Process name - used as stable identifier for grouping
+    let id: String
 
     /// Name of the process owning these ports
     let processName: String
 
-    /// All ports owned by this process
+    /// All PIDs in this group
+    let pids: [Int]
+
+    /// All ports owned by this process (across all PIDs)
     let ports: [PortInfo]
 }

platforms/macos/Sources/Services/PortGroupingService.swift

@@ -33,11 +33,12 @@ actor PortGroupingService {
     /// // groups[0] might contain: ProcessGroup(id: 1234, processName: "node", ports: [3000, 3001])
     /// ```
     func groupByProcess(_ ports: [PortInfo]) -> [ProcessGroup] {
-        let grouped = Dictionary(grouping: ports) { $0.pid }
-        return grouped.map { pid, ports in
+        let grouped = Dictionary(grouping: ports) { $0.processName }
+        return grouped.map { name, ports in
             ProcessGroup(
-                id: pid,
-                processName: ports.first?.processName ?? "Unknown",
+                id: name,
+                processName: name,
+                pids: Array(Set(ports.map(\.pid))).sorted(),
                 ports: ports.sorted { $0.port < $1.port }
             )
         }.sorted { $0.processName.localizedCaseInsensitiveCompare($1.processName) == .orderedAscending }
@@ -54,11 +55,12 @@ actor PortGroupingService {
     ///   - watched: Set of watched port numbers
     /// - Returns: Array of ProcessGroup instances, sorted by priority then name
     func groupByProcessWithPriority(_ ports: [PortInfo], favorites: Set<Int>, watched: Set<Int>) -> [ProcessGroup] {
-        let grouped = Dictionary(grouping: ports) { $0.pid }
-        return grouped.map { pid, ports in
+        let grouped = Dictionary(grouping: ports) { $0.processName }
+        return grouped.map { name, ports in
             ProcessGroup(
-                id: pid,
-                processName: ports.first?.processName ?? "Unknown",
+                id: name,
+                processName: name,
+                pids: Array(Set(ports.map(\.pid))).sorted(),
                 ports: ports.sorted { $0.port < $1.port }
             )
         }.sorted { a, b in

platforms/macos/Sources/Views/Components/ProcessGroupRow.swift

@@ -48,11 +48,12 @@ struct ProcessGroupListRow: View {
             }
             .frame(width: 150, alignment: .leading)
 
-            // PID (aligned with PID column of header)
-            Text("\(group.id)")
+            // PID(s) (aligned with PID column of header)
+            Text(group.pids.count == 1 ? "\(group.pids[0])" : "\(group.pids.count) PIDs")
                 .font(.system(.body, design: .monospaced))
                 .foregroundStyle(.secondary)
                 .frame(width: 70, alignment: .leading)
+                .help(group.pids.map(String.init).joined(separator: ", "))
 
             // Port Count Badge (aligned with Type column of header effectively)
             if !showConfirm {

platforms/macos/Sources/Views/MenuBar/MenuBarPortList.swift

@@ -14,7 +14,7 @@ struct MenuBarPortList: View {
     let filteredPortForwardConnections: [PortForwardConnectionState]
     let groupedByProcess: [ProcessGroup]
     let useTreeView: Bool
-    @Binding var expandedProcesses: Set<Int>
+    @Binding var expandedProcesses: Set<String>
     @Binding var confirmingKillPort: String?
     @Bindable var state: AppState
 

platforms/macos/Sources/Views/MenuBar/MenuBarProcessGroupRow.swift

@@ -23,7 +23,7 @@ struct MenuBarProcessGroupRow: View {
                     if group.ports.contains(where: { state.isWatching($0.port) }) { Image(systemName: "eye.fill").font(.caption2).foregroundStyle(.blue) }
                 }
                 Spacer()
-                Text("PID \(String(group.id))").font(.caption2).foregroundStyle(.secondary)
+                Text(group.pids.count == 1 ? "PID \(group.pids[0])" : "\(group.pids.count) PIDs").font(.caption2).foregroundStyle(.secondary)
                 if !(isHovered || showConfirm) {
                     Text("\(group.ports.count)").font(.caption2).foregroundStyle(.secondary).padding(.horizontal, 5).background(.tertiary.opacity(0.5)).clipShape(Capsule())
                 } else if !showConfirm {

platforms/macos/Sources/Views/MenuBar/MenuBarView.swift

@@ -16,7 +16,7 @@ struct MenuBarView: View {
     @State private var confirmingKillAll = false
     @State private var confirmingKillPort: String?
     @State private var hoveredPort: String?
-    @State private var expandedProcesses: Set<Int> = []
+    @State private var expandedProcesses: Set<String> = []
     @Default(.useTreeView) private var useTreeView
     @Default(.hideSystemProcesses) private var hideSystemProcesses
 
@@ -70,11 +70,12 @@ struct MenuBarView: View {
         }
 
         // Compute groups from cached filtered ports
-        let grouped = Dictionary(grouping: cachedFilteredPorts) { $0.pid }
-        cachedGroups = grouped.map { pid, ports in
+        let grouped = Dictionary(grouping: cachedFilteredPorts) { $0.processName }
+        cachedGroups = grouped.map { name, ports in
             ProcessGroup(
-                id: pid,
-                processName: ports.first?.processName ?? "Unknown",
+                id: name,
+                processName: name,
+                pids: Array(Set(ports.map(\.pid))).sorted(),
                 ports: ports.sorted { $0.port < $1.port }
             )
         }.sorted { a, b in

platforms/macos/Sources/Views/PortTable/PortTableView.swift

@@ -17,7 +17,7 @@ struct PortTableView: View {
     @State private var sortOrder: SortOrder = .port
     @State private var sortAscending = true
     @Default(.useTreeView) private var useTreeView
-    @State private var expandedProcesses: Set<Int> = []
+    @State private var expandedProcesses: Set<String> = []
 
     var body: some View {
         VStack(spacing: 0) {
@@ -206,11 +206,12 @@ struct PortTableView: View {
 
     /// Groups ports by process for tree view
     private var groupedPorts: [ProcessGroup] {
-        let grouped = Dictionary(grouping: appState.filteredPorts) { $0.pid }
-        return grouped.map { pid, ports in
+        let grouped = Dictionary(grouping: appState.filteredPorts) { $0.processName }
+        return grouped.map { name, ports in
             ProcessGroup(
-                id: pid,
-                processName: ports.first?.processName ?? "Unknown",
+                id: name,
+                processName: name,
+                pids: Array(Set(ports.map(\.pid))).sorted(),
                 ports: ports.sorted { $0.port < $1.port }
             )
         }.sorted { $0.processName.localizedCaseInsensitiveCompare($1.processName) == .orderedAscending }