fix(agent-resume): resume from launch directory, not drifted cwd

CLI/cmux.swift

@@ -24320,7 +24320,7 @@ struct CMUXCLI {
             "command": command,
             "auto_resume": true
         ]
-        if let cwd = normalizedHookValue(cwd) ?? normalizedHookValue(launchCommand?.workingDirectory) {
+        if let cwd = normalizedHookValue(launchCommand?.workingDirectory) ?? normalizedHookValue(cwd) {
             params["cwd"] = cwd
         }
         if let resumeEnvironment, !resumeEnvironment.isEmpty {
@@ -24402,7 +24402,7 @@ struct CMUXCLI {
         guard let argv, !argv.isEmpty else { return nil }
         return agentSurfaceResumeShellCommand(
             argv: argv,
-            workingDirectory: workingDirectory ?? launchCommand?.workingDirectory,
+            workingDirectory: launchCommand?.workingDirectory ?? workingDirectory,
             kind: kind,
             environment: environment
         )

Sources/RestorableAgentSession.swift

@@ -362,7 +362,7 @@ enum AgentResumeCommandBuilder {
 
         let cwd = !includeWorkingDirectoryPrefix || customRegistration?.cwd == .ignore
             ? nil
-            : normalized(workingDirectory ?? launchCommand?.workingDirectory)
+            : normalized(launchCommand?.workingDirectory ?? workingDirectory)
         let sanitizedCommandParts = customRegistration == nil
             ? AgentLaunchSanitizer.removingSavedWorkingDirectoryOptions(
                 from: commandParts,
@@ -666,11 +666,14 @@ enum AgentResumeCommandBuilder {
         let sessionDirectory = normalized(registration.sessionDirectory).map {
             ($0 as NSString).expandingTildeInPath
         }
+        let resolvedCwd = registration.cwd == .ignore
+            ? nil
+            : normalized(launchCommand?.workingDirectory ?? workingDirectory)
         let replacements: [String: String] = [
             "sessionId": sessionId,
             "sessionPath": sessionId,
             "executable": original.executable,
-            "cwd": normalized(workingDirectory ?? launchCommand?.workingDirectory) ?? "",
+            "cwd": resolvedCwd ?? "",
             "sessionDir": sessionDirectory ?? "",
         ]
         var resolved: [String] = []

cmuxTests/RestorableAgentHookProviderResumeTests.swift

@@ -1,4 +1,5 @@
 import CMUXAgentLaunch
+import Testing
 import XCTest
 
 #if canImport(cmux_DEV)
@@ -641,3 +642,90 @@ extension SocketListenerAcceptPolicyTests {
         )
     }
 }
+
+@Suite
+struct RestorableAgentResumeWorkingDirectoryTests {
+    @Test
+    func claudeResumeCommandChangesToLaunchDirectoryNotDriftedCwd() {
+        let snapshot = SessionRestorableAgentSnapshot(
+            kind: .claude,
+            sessionId: "59729506-e83c-4bfe-a730-1d50d10cc396",
+            workingDirectory: "/tmp/claude repo/nested",
+            launchCommand: AgentLaunchCommandSnapshot(
+                launcher: "claude",
+                executablePath: "/Users/example/.local/bin/claude",
+                arguments: ["/Users/example/.local/bin/claude"],
+                workingDirectory: "/tmp/claude repo",
+                environment: nil,
+                capturedAt: 123,
+                source: "process"
+            )
+        )
+
+        #expect(
+            snapshot.resumeCommand
+                == "{ cd -- '/tmp/claude repo' 2>/dev/null || [ ! -d '/tmp/claude repo' ]; } && '/Users/example/.local/bin/claude' '--resume' '59729506-e83c-4bfe-a730-1d50d10cc396'"
+        )
+    }
+
+    @Test
+    func customVaultResumeTemplateUsesLaunchDirectoryNotDriftedCwd() throws {
+        let snapshot = SessionRestorableAgentSnapshot(
+            kind: .custom("vault-tool"),
+            sessionId: "session-123",
+            workingDirectory: "/tmp/vault-drifted",
+            launchCommand: AgentLaunchCommandSnapshot(
+                launcher: "vault-tool",
+                executablePath: "/usr/local/bin/vault-tool",
+                arguments: ["/usr/local/bin/vault-tool"],
+                workingDirectory: "/tmp/vault-launch",
+                environment: nil,
+                capturedAt: 123,
+                source: "process"
+            ),
+            registration: CmuxVaultAgentRegistration(
+                id: "vault-tool",
+                name: "Vault Tool",
+                detect: CmuxVaultAgentDetectRule(processName: "vault-tool"),
+                sessionIdSource: .argvOption("--resume"),
+                resumeCommand: "{{executable}} --resume {{sessionId}} --dir {{cwd}}",
+                cwd: .preserve
+            )
+        )
+
+        let command = try #require(snapshot.resumeCommand)
+        #expect(command.contains("/tmp/vault-launch"))
+        #expect(!command.contains("/tmp/vault-drifted"))
+    }
+
+    @Test
+    func customVaultResumeTemplateSuppressesCwdWhenIgnored() {
+        let snapshot = SessionRestorableAgentSnapshot(
+            kind: .custom("vault-tool"),
+            sessionId: "session-123",
+            workingDirectory: "/tmp/vault-drifted",
+            launchCommand: AgentLaunchCommandSnapshot(
+                launcher: "vault-tool",
+                executablePath: "/usr/local/bin/vault-tool",
+                arguments: ["/usr/local/bin/vault-tool"],
+                workingDirectory: "/tmp/vault-launch",
+                environment: nil,
+                capturedAt: 123,
+                source: "process"
+            ),
+            registration: CmuxVaultAgentRegistration(
+                id: "vault-tool",
+                name: "Vault Tool",
+                detect: CmuxVaultAgentDetectRule(processName: "vault-tool"),
+                sessionIdSource: .argvOption("--resume"),
+                resumeCommand: "{{executable}} --resume {{sessionId}} --dir {{cwd}}",
+                cwd: .ignore
+            )
+        )
+
+        // cwd: .ignore must keep the launch dir out of the resolved command entirely.
+        let command = snapshot.resumeCommand ?? ""
+        #expect(!command.contains("/tmp/vault-launch"))
+        #expect(!command.contains("/tmp/vault-drifted"))
+    }
+}