feat(worktree): run user-configured post-create command

Adds a Settings field for a shell command that runs after worktree
creation with $WORKTREE_DIRECTORY set to the new path. Useful for
e.g. `mise trust $WORKTREE_DIRECTORY`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: neerajsingh0101

Sources/NeetlyApp/GitWorktree.swift

@@ -198,6 +198,7 @@ class GitWorktree {
         // If worktree already exists, just use it
         if FileManager.default.fileExists(atPath: worktreePath) {
             NSLog("GitWorktree: worktree already exists at \(worktreePath)")
+            runPostCreateCommand(at: worktreePath)
             return .success(path: worktreePath)
         }
 
@@ -242,6 +243,7 @@ class GitWorktree {
         NSLog("GitWorktree: \(cmd1) → \(result1)")
 
         if result1.success {
+            runPostCreateCommand(at: worktreePath)
             return .success(path: worktreePath)
         }
 
@@ -251,12 +253,23 @@ class GitWorktree {
         NSLog("GitWorktree: \(cmd2) → \(result2)")
 
         if result2.success {
+            runPostCreateCommand(at: worktreePath)
             return .success(path: worktreePath)
         }
 
         return .failure(message: "Failed: \(result1.output) / \(result2.output)")
     }
 
+    /// Run the user-configured post-create command (Settings → Post-Create
+    /// Command) with `$WORKTREE_DIRECTORY` set to the new worktree's path.
+    /// Best-effort: failures log but don't block. No-op when unconfigured.
+    private func runPostCreateCommand(at path: String) {
+        let cmd = NeetlySettings.shared.postWorktreeCreateCommand.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !cmd.isEmpty else { return }
+        let result = shell(cmd, in: repoPath, extraEnv: ["WORKTREE_DIRECTORY": path])
+        NSLog("GitWorktree: post-create command → \(result)")
+    }
+
     private func detectDefaultBranch() -> String {
         let result = shell("git symbolic-ref refs/remotes/origin/HEAD", in: repoPath)
         if result.success {
@@ -279,11 +292,15 @@ class GitWorktree {
     }
 
     /// Run a shell command via /bin/zsh -c to get proper PATH and env.
-    private func shell(_ command: String, in directory: String) -> ShellResult {
+    /// Pass `extraEnv` to add or override environment variables for the child.
+    private func shell(_ command: String, in directory: String, extraEnv: [String: String]? = nil) -> ShellResult {
         let process = Process()
         process.executableURL = URL(fileURLWithPath: "/bin/zsh")
         process.arguments = ["-l", "-c", command]
         process.currentDirectoryURL = URL(fileURLWithPath: directory)
+        if let extraEnv {
+            process.environment = ProcessInfo.processInfo.environment.merging(extraEnv) { _, new in new }
+        }
 
         let outPipe = Pipe()
         let errPipe = Pipe()

Sources/NeetlyApp/NeetlySettings.swift

@@ -15,6 +15,9 @@ class NeetlySettings {
     private struct Settings: Codable {
         var worktreeBaseDir: String
         var diffCommand: String?
+        /// Shell command to run after a worktree is created. The variable
+        /// `$WORKTREE_DIRECTORY` is set to the new worktree's absolute path.
+        var postWorktreeCreateCommand: String?
     }
 
     static var defaultWorktreeBaseDir: String {
@@ -43,6 +46,16 @@ class NeetlySettings {
         save(s)
     }
 
+    var postWorktreeCreateCommand: String {
+        load().postWorktreeCreateCommand ?? ""
+    }
+
+    func setPostWorktreeCreateCommand(_ command: String) {
+        var s = load()
+        s.postWorktreeCreateCommand = command
+        save(s)
+    }
+
     private func load() -> Settings {
         guard let data = try? Data(contentsOf: settingsFile),
               let settings = try? JSONDecoder().decode(Settings.self, from: data) else {

Sources/NeetlyApp/SetupView.swift

@@ -768,6 +768,7 @@ struct DeleteWorktreeSheet: View {
 struct SettingsScreen: View {
     @State private var worktreeDir: String = NeetlySettings.shared.worktreeBaseDir
     @State private var diffCommand: String = NeetlySettings.shared.diffCommand
+    @State private var postCreateCommand: String = NeetlySettings.shared.postWorktreeCreateCommand
     @State private var message: String?
     @State private var messageIsError: Bool = false
     var onBack: () -> Void
@@ -811,6 +812,18 @@ struct SettingsScreen: View {
                         }
                     }
 
+                    // Post-create command
+                    VStack(alignment: .leading, spacing: 8) {
+                        Text("Post-Create Command")
+                            .font(.system(size: 16, weight: .medium))
+                        Text("Runs after a new worktree is created. Use $WORKTREE_DIRECTORY for the worktree's absolute path. Leave blank to skip. A common use case is running mise trust $WORKTREE_DIRECTORY for the folks who use mise to manage their Ruby versions.")
+                            .font(.system(size: 13))
+                            .foregroundColor(.secondary)
+                        TextField("e.g. mise trust $WORKTREE_DIRECTORY", text: $postCreateCommand)
+                            .textFieldStyle(.roundedBorder)
+                            .font(.system(size: 15, design: .monospaced))
+                    }
+
                     Divider()
 
                     // Cmd+D: Open Diff
@@ -901,6 +914,10 @@ struct SettingsScreen: View {
             let cmd = diffCommand.trimmingCharacters(in: .whitespaces)
             NeetlySettings.shared.setDiffCommand(cmd.isEmpty ? NeetlySettings.defaultDiffCommand : cmd)
 
+            NeetlySettings.shared.setPostWorktreeCreateCommand(
+                postCreateCommand.trimmingCharacters(in: .whitespacesAndNewlines)
+            )
+
             message = "Settings saved."
             messageIsError = false
         } else {