feat: Add Hermes process start/stop/restart controls (#10)

- Add hermesPID() and stopHermes() to HermesFileService for process
  signal management via SIGTERM
- Add process control bar to Health view with running status, PID
  display, and Start/Stop/Restart buttons
- Add Start/Stop/Restart Hermes quick actions to menu bar
- Start launches gateway, stop sends SIGTERM, restart combines both

Closes #10

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

scarf/scarf/Core/Services/HermesFileService.swift

@@ -235,6 +235,10 @@ struct HermesFileService: Sendable {
     // MARK: - Hermes Process
 
     func isHermesRunning() -> Bool {
+        hermesPID() != nil
+    }
+
+    func hermesPID() -> pid_t? {
         let pipe = Pipe()
         let process = Process()
         process.executableURL = URL(fileURLWithPath: "/usr/bin/pgrep")
@@ -245,12 +249,21 @@ struct HermesFileService: Sendable {
             try process.run()
             process.waitUntilExit()
             let data = pipe.fileHandleForReading.readDataToEndOfFile()
-            return !data.isEmpty
+            let output = String(data: data, encoding: .utf8) ?? ""
+            guard let firstLine = output.components(separatedBy: "\n").first(where: { !$0.isEmpty }),
+                  let pid = pid_t(firstLine.trimmingCharacters(in: .whitespaces)) else { return nil }
+            return pid
         } catch {
-            return false
+            return nil
         }
     }
 
+    @discardableResult
+    func stopHermes() -> Bool {
+        guard let pid = hermesPID() else { return false }
+        return kill(pid, SIGTERM) == 0
+    }
+
     // MARK: - File I/O
 
     private func readFile(_ path: String) -> String? {

scarf/scarf/Features/Health/ViewModels/HealthViewModel.swift

@@ -22,6 +22,8 @@ struct HealthSection: Identifiable {
 
 @Observable
 final class HealthViewModel {
+    private let fileService = HermesFileService()
+
     var version = ""
     var updateInfo = ""
     var hasUpdate = false
@@ -31,9 +33,13 @@ final class HealthViewModel {
     var warningCount = 0
     var okCount = 0
     var isLoading = false
+    var hermesRunning = false
+    var hermesPID: pid_t?
+    var actionMessage: String?
 
     func load() {
         isLoading = true
+        refreshProcessStatus()
         loadVersion()
         let statusOutput = runHermes(["status"]).output
         statusSections = parseOutput(statusOutput)
@@ -43,6 +49,41 @@ final class HealthViewModel {
         isLoading = false
     }
 
+    func refreshProcessStatus() {
+        hermesPID = fileService.hermesPID()
+        hermesRunning = hermesPID != nil
+    }
+
+    func stopHermes() {
+        fileService.stopHermes()
+        actionMessage = "Stop signal sent"
+        DispatchQueue.main.asyncAfter(deadline: .now() + 2) { [weak self] in
+            self?.refreshProcessStatus()
+            self?.actionMessage = nil
+        }
+    }
+
+    func startHermes() {
+        runHermes(["gateway", "start"])
+        actionMessage = "Start requested"
+        DispatchQueue.main.asyncAfter(deadline: .now() + 3) { [weak self] in
+            self?.refreshProcessStatus()
+            self?.actionMessage = nil
+        }
+    }
+
+    func restartHermes() {
+        fileService.stopHermes()
+        actionMessage = "Restarting..."
+        DispatchQueue.main.asyncAfter(deadline: .now() + 2) { [weak self] in
+            self?.runHermes(["gateway", "start"])
+            DispatchQueue.main.asyncAfter(deadline: .now() + 3) { [weak self] in
+                self?.refreshProcessStatus()
+                self?.actionMessage = nil
+            }
+        }
+    }
+
     private func loadVersion() {
         let output = runHermes(["version"]).output
         let lines = output.components(separatedBy: "\n")

scarf/scarf/Features/Health/Views/HealthView.swift

@@ -29,6 +29,7 @@ struct HealthView: View {
     // MARK: - Header
 
     private var headerBar: some View {
+        VStack(spacing: 0) {
             HStack(spacing: 16) {
                 if !viewModel.version.isEmpty {
                     Text(viewModel.version)
@@ -59,6 +60,44 @@ struct HealthView: View {
             }
             .padding(.horizontal)
             .padding(.vertical, 8)
+
+            Divider()
+
+            HStack(spacing: 16) {
+                HStack(spacing: 6) {
+                    Circle()
+                        .fill(viewModel.hermesRunning ? .green : .red)
+                        .frame(width: 8, height: 8)
+                    Text(viewModel.hermesRunning ? "Hermes Running" : "Hermes Stopped")
+                        .font(.caption.bold())
+                    if let pid = viewModel.hermesPID {
+                        Text("PID \(pid)")
+                            .font(.caption.monospaced())
+                            .foregroundStyle(.secondary)
+                    }
+                }
+
+                if let msg = viewModel.actionMessage {
+                    Label(msg, systemImage: "arrow.triangle.2.circlepath")
+                        .font(.caption)
+                        .foregroundStyle(.orange)
+                }
+
+                Spacer()
+
+                HStack(spacing: 8) {
+                    Button("Start") { viewModel.startHermes() }
+                        .disabled(viewModel.hermesRunning)
+                    Button("Stop") { viewModel.stopHermes() }
+                        .disabled(!viewModel.hermesRunning)
+                    Button("Restart") { viewModel.restartHermes() }
+                        .disabled(!viewModel.hermesRunning)
+                }
+                .controlSize(.small)
+            }
+            .padding(.horizontal)
+            .padding(.vertical, 8)
+        }
     }
 
     // MARK: - Grid

scarf/scarf/scarfApp.swift

@@ -54,6 +54,33 @@ final class MenuBarStatus {
         timer = nil
     }
 
+    func startHermes() {
+        let process = Process()
+        process.executableURL = URL(fileURLWithPath: HermesPaths.hermesBinary)
+        process.arguments = ["gateway", "start"]
+        process.standardOutput = Pipe()
+        process.standardError = Pipe()
+        try? process.run()
+        process.waitUntilExit()
+        DispatchQueue.main.asyncAfter(deadline: .now() + 3) { [weak self] in
+            self?.refresh()
+        }
+    }
+
+    func stopHermes() {
+        fileService.stopHermes()
+        DispatchQueue.main.asyncAfter(deadline: .now() + 2) { [weak self] in
+            self?.refresh()
+        }
+    }
+
+    func restartHermes() {
+        fileService.stopHermes()
+        DispatchQueue.main.asyncAfter(deadline: .now() + 2) { [weak self] in
+            self?.startHermes()
+        }
+    }
+
     private func refresh() {
         hermesRunning = fileService.isHermesRunning()
         gatewayRunning = fileService.loadGatewayState()?.isRunning ?? false
@@ -69,6 +96,13 @@ struct MenuBarMenu: View {
             Label(status.hermesRunning ? "Hermes Running" : "Hermes Stopped", systemImage: status.hermesRunning ? "circle.fill" : "circle")
             Label(status.gatewayRunning ? "Gateway Running" : "Gateway Stopped", systemImage: status.gatewayRunning ? "circle.fill" : "circle")
             Divider()
+            Button("Start Hermes") { status.startHermes() }
+                .disabled(status.hermesRunning)
+            Button("Stop Hermes") { status.stopHermes() }
+                .disabled(!status.hermesRunning)
+            Button("Restart Hermes") { status.restartHermes() }
+                .disabled(!status.hermesRunning)
+            Divider()
             Button("Open Dashboard") {
                 coordinator.selectedSection = .dashboard
                 NSApplication.shared.activate()