Add session management: rename, delete, export, and stats bar

Sessions browser enhancements:
- Stats bar: total sessions, messages, DB size, per-platform counts
- Right-click context menu on session rows: Rename, Export, Delete
- Detail view actions menu (ellipsis button): same actions
- Rename: sheet with text field, calls hermes sessions rename
- Delete: confirmation dialog, calls hermes sessions delete --yes
- Export single session: NSSavePanel, calls hermes sessions export
- Export all: button in stats bar, exports everything to JSONL
- Session ID shown in detail header for reference

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scarf/scarf/Features/Sessions/ViewModels/SessionsViewModel.swift

@@ -1,4 +1,13 @@
 import Foundation
+import AppKit
+import UniformTypeIdentifiers
+
+struct SessionStoreStats {
+    let totalSessions: Int
+    let totalMessages: Int
+    let databaseSize: String
+    let platformCounts: [(platform: String, count: Int)]
+}
 
 @Observable
 final class SessionsViewModel {
@@ -11,12 +20,20 @@ final class SessionsViewModel {
     var searchText = ""
     var searchResults: [HermesMessage] = []
     var isSearching = false
+    var storeStats: SessionStoreStats?
+
+    var renameSessionId: String?
+    var renameText = ""
+    var showRenameSheet = false
+    var showDeleteConfirmation = false
+    var deleteSessionId: String?
 
     func load() async {
         let opened = await dataService.open()
         guard opened else { return }
         sessions = await dataService.fetchSessions(limit: 500)
         sessionPreviews = await dataService.fetchSessionPreviews(limit: 500)
+        computeStats()
     }
 
     func previewFor(_ session: HermesSession) -> String {
@@ -50,4 +67,127 @@ final class SessionsViewModel {
     func cleanup() async {
         await dataService.close()
     }
+
+    // MARK: - Session Actions
+
+    func beginRename(_ session: HermesSession) {
+        renameSessionId = session.id
+        renameText = previewFor(session)
+        showRenameSheet = true
+    }
+
+    func confirmRename() {
+        guard let sessionId = renameSessionId else { return }
+        let title = renameText.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !title.isEmpty else { return }
+        let result = runHermes(["sessions", "rename", sessionId, title])
+        if result.exitCode == 0 {
+            if let idx = sessions.firstIndex(where: { $0.id == sessionId }) {
+                sessions[idx] = HermesSession(
+                    id: sessions[idx].id, source: sessions[idx].source,
+                    userId: sessions[idx].userId, model: sessions[idx].model,
+                    title: title, parentSessionId: sessions[idx].parentSessionId,
+                    startedAt: sessions[idx].startedAt, endedAt: sessions[idx].endedAt,
+                    endReason: sessions[idx].endReason, messageCount: sessions[idx].messageCount,
+                    toolCallCount: sessions[idx].toolCallCount, inputTokens: sessions[idx].inputTokens,
+                    outputTokens: sessions[idx].outputTokens, cacheReadTokens: sessions[idx].cacheReadTokens,
+                    cacheWriteTokens: sessions[idx].cacheWriteTokens,
+                    estimatedCostUSD: sessions[idx].estimatedCostUSD
+                )
+            }
+        }
+        showRenameSheet = false
+        renameSessionId = nil
+    }
+
+    func beginDelete(_ session: HermesSession) {
+        deleteSessionId = session.id
+        showDeleteConfirmation = true
+    }
+
+    func confirmDelete() {
+        guard let sessionId = deleteSessionId else { return }
+        let result = runHermes(["sessions", "delete", "--yes", sessionId])
+        if result.exitCode == 0 {
+            sessions.removeAll { $0.id == sessionId }
+            if selectedSession?.id == sessionId {
+                selectedSession = nil
+                messages = []
+            }
+            computeStats()
+        }
+        showDeleteConfirmation = false
+        deleteSessionId = nil
+    }
+
+    func exportSession(_ session: HermesSession) {
+        let panel = NSSavePanel()
+        panel.nameFieldStringValue = "\(session.id).jsonl"
+        panel.allowedContentTypes = [.json]
+        panel.canCreateDirectories = true
+        guard panel.runModal() == .OK, let url = panel.url else { return }
+        runHermes(["sessions", "export", url.path, "--session-id", session.id])
+    }
+
+    func exportAll() {
+        let panel = NSSavePanel()
+        panel.nameFieldStringValue = "hermes-sessions.jsonl"
+        panel.allowedContentTypes = [.json]
+        panel.canCreateDirectories = true
+        guard panel.runModal() == .OK, let url = panel.url else { return }
+        runHermes(["sessions", "export", url.path])
+    }
+
+    // MARK: - Stats
+
+    private func computeStats() {
+        let totalMessages = sessions.reduce(0) { $0 + $1.messageCount }
+
+        var platformCounts: [String: Int] = [:]
+        for s in sessions {
+            platformCounts[s.source, default: 0] += 1
+        }
+        let sorted = platformCounts.sorted { $0.value > $1.value }.map { (platform: $0.key, count: $0.value) }
+
+        let dbPath = HermesPaths.stateDB
+        let fileSize: String
+        if let attrs = try? FileManager.default.attributesOfItem(atPath: dbPath),
+           let size = attrs[.size] as? Int {
+            if size >= 1_048_576 {
+                fileSize = String(format: "%.1f MB", Double(size) / 1_048_576)
+            } else {
+                fileSize = String(format: "%.0f KB", Double(size) / 1_024)
+            }
+        } else {
+            fileSize = "unknown"
+        }
+
+        storeStats = SessionStoreStats(
+            totalSessions: sessions.count,
+            totalMessages: totalMessages,
+            databaseSize: fileSize,
+            platformCounts: sorted
+        )
+    }
+
+    // MARK: - Hermes CLI
+
+    @discardableResult
+    private func runHermes(_ arguments: [String]) -> (output: String, exitCode: Int32) {
+        let process = Process()
+        process.executableURL = URL(fileURLWithPath: HermesPaths.hermesBinary)
+        process.arguments = arguments
+        let pipe = Pipe()
+        process.standardOutput = pipe
+        process.standardError = Pipe()
+        do {
+            try process.run()
+            process.waitUntilExit()
+            let data = pipe.fileHandleForReading.readDataToEndOfFile()
+            let output = String(data: data, encoding: .utf8) ?? ""
+            return (output, process.terminationStatus)
+        } catch {
+            return ("", -1)
+        }
+    }
 }

scarf/scarf/Features/Sessions/Views/SessionDetailView.swift

@@ -4,6 +4,9 @@ struct SessionDetailView: View {
     let session: HermesSession
     let messages: [HermesMessage]
     var preview: String?
+    var onRename: (() -> Void)?
+    var onExport: (() -> Void)?
+    var onDelete: (() -> Void)?
 
     var body: some View {
         VStack(alignment: .leading, spacing: 0) {
@@ -16,22 +19,41 @@ struct SessionDetailView: View {
 
     private var sessionHeader: some View {
         VStack(alignment: .leading, spacing: 6) {
-            Text(preview ?? session.displayTitle)
-                .font(.title3.bold())
+            HStack {
+                Text(preview ?? session.displayTitle)
+                    .font(.title3.bold())
+                Spacer()
+                if onRename != nil || onExport != nil || onDelete != nil {
+                    Menu {
+                        if let onRename { Button("Rename...") { onRename() } }
+                        if let onExport { Button("Export...") { onExport() } }
+                        if let onDelete {
+                            Divider()
+                            Button("Delete...", role: .destructive) { onDelete() }
+                        }
+                    } label: {
+                        Image(systemName: "ellipsis.circle")
+                            .foregroundStyle(.secondary)
+                    }
+                    .menuStyle(.borderlessButton)
+                    .fixedSize()
+                }
+            }
             HStack(spacing: 16) {
                 Label(session.source, systemImage: session.sourceIcon)
                 Label(session.model ?? "unknown", systemImage: "cpu")
                 Label("\(session.messageCount) msgs", systemImage: "bubble.left")
                 Label("\(session.toolCallCount) tools", systemImage: "wrench")
-                if let cost = session.estimatedCostUSD {
-                    Label(String(format: "$%.4f", cost), systemImage: "dollarsign.circle")
-                }
                 if let date = session.startedAt {
                     Label(date.formatted(.dateTime.month().day().hour().minute()), systemImage: "calendar")
                 }
             }
             .font(.caption)
             .foregroundStyle(.secondary)
+            Text(session.id)
+                .font(.caption2.monospaced())
+                .foregroundStyle(.tertiary)
+                .textSelection(.enabled)
         }
         .padding()
     }

scarf/scarf/Features/Sessions/Views/SessionsView.swift

@@ -5,11 +5,17 @@ struct SessionsView: View {
     @Environment(AppCoordinator.self) private var coordinator
 
     var body: some View {
-        HSplitView {
-            sessionList
-                .frame(minWidth: 280, idealWidth: 320)
-            sessionDetail
-                .frame(minWidth: 400)
+        VStack(spacing: 0) {
+            if let stats = viewModel.storeStats {
+                statsBar(stats)
+                Divider()
+            }
+            HSplitView {
+                sessionList
+                    .frame(minWidth: 280, idealWidth: 320)
+                sessionDetail
+                    .frame(minWidth: 400)
+            }
         }
         .navigationTitle("Sessions")
         .searchable(text: $viewModel.searchText, prompt: "Search messages...")
@@ -28,6 +34,33 @@ struct SessionsView: View {
             }
         }
         .onDisappear { Task { await viewModel.cleanup() } }
+        .sheet(isPresented: $viewModel.showRenameSheet) {
+            renameSheet
+        }
+        .confirmationDialog("Delete Session?", isPresented: $viewModel.showDeleteConfirmation) {
+            Button("Delete", role: .destructive) { viewModel.confirmDelete() }
+            Button("Cancel", role: .cancel) {}
+        } message: {
+            Text("This will permanently delete the session and all its messages.")
+        }
+    }
+
+    private func statsBar(_ stats: SessionStoreStats) -> some View {
+        HStack(spacing: 16) {
+            Label("\(stats.totalSessions) sessions", systemImage: "bubble.left.and.bubble.right")
+            Label("\(stats.totalMessages) messages", systemImage: "text.bubble")
+            Label(stats.databaseSize, systemImage: "internaldrive")
+            ForEach(stats.platformCounts, id: \.platform) { item in
+                Label("\(item.count) \(item.platform)", systemImage: platformIcon(item.platform))
+            }
+            Spacer()
+            Button("Export All") { viewModel.exportAll() }
+                .controlSize(.small)
+        }
+        .font(.caption)
+        .foregroundStyle(.secondary)
+        .padding(.horizontal)
+        .padding(.vertical, 6)
     }
 
     private var sessionList: some View {
@@ -64,6 +97,12 @@ struct SessionsView: View {
                 ForEach(viewModel.sessions) { session in
                     SessionRow(session: session, preview: viewModel.previewFor(session))
                         .tag(session.id)
+                        .contextMenu {
+                            Button("Rename...") { viewModel.beginRename(session) }
+                            Button("Export...") { viewModel.exportSession(session) }
+                            Divider()
+                            Button("Delete...", role: .destructive) { viewModel.beginDelete(session) }
+                        }
                 }
             }
         }
@@ -73,11 +112,50 @@ struct SessionsView: View {
     @ViewBuilder
     private var sessionDetail: some View {
         if let session = viewModel.selectedSession {
-            SessionDetailView(session: session, messages: viewModel.messages, preview: viewModel.previewFor(session))
-                .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .topLeading)
+            SessionDetailView(
+                session: session,
+                messages: viewModel.messages,
+                preview: viewModel.previewFor(session),
+                onRename: { viewModel.beginRename(session) },
+                onExport: { viewModel.exportSession(session) },
+                onDelete: { viewModel.beginDelete(session) }
+            )
+            .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .topLeading)
         } else {
             ContentUnavailableView("Select a Session", systemImage: "bubble.left.and.bubble.right", description: Text("Choose a session from the list"))
                 .frame(maxWidth: .infinity, maxHeight: .infinity)
         }
     }
+
+    private var renameSheet: some View {
+        VStack(spacing: 16) {
+            Text("Rename Session")
+                .font(.headline)
+            TextField("Session title", text: $viewModel.renameText)
+                .textFieldStyle(.roundedBorder)
+                .onSubmit { viewModel.confirmRename() }
+            HStack {
+                Button("Cancel") { viewModel.showRenameSheet = false }
+                    .keyboardShortcut(.cancelAction)
+                Spacer()
+                Button("Rename") { viewModel.confirmRename() }
+                    .buttonStyle(.borderedProminent)
+                    .keyboardShortcut(.defaultAction)
+                    .disabled(viewModel.renameText.trimmingCharacters(in: .whitespaces).isEmpty)
+            }
+        }
+        .padding()
+        .frame(width: 400)
+    }
+
+    private func platformIcon(_ platform: String) -> String {
+        switch platform {
+        case "cli": return "terminal"
+        case "telegram": return "paperplane"
+        case "discord": return "bubble.left.and.bubble.right"
+        case "slack": return "number"
+        case "email": return "envelope"
+        default: return "bubble.left"
+        }
+    }
 }