Make install command non-destructive with merge support

- Remove destructive `removeItem()` call - all installs now merge files
- Add support for `--path .` or `--path current` to install into current directory
- Add safety check to verify current directory is in expected `.codex/skills` or `.claude/skills` location
- Add user confirmation prompt when installing to current directory
- Update help text to document current directory option

This change ensures users never lose existing work when installing skills, whether using default paths, custom paths, or current directory installation.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: ibrahimkteish

Sources/pfw/Install.swift

@@ -27,7 +27,7 @@ struct Install: AsyncParsableCommand {
   )
   var tool: Tool = .codex
 
-  @Option(help: "Directory to install skills into.")
+  @Option(help: "Directory to install skills into. Use '.' or 'current' for current directory.")
   var path: String?
 
   func run() async throws {
@@ -68,9 +68,46 @@ struct Install: AsyncParsableCommand {
     let zipURL = URL.temporaryDirectory.appending(path: UUID().uuidString)
     try data.write(to: zipURL)
 
-    let installURL = URL(fileURLWithPath: path ?? tool.defaultInstallPath.path)
-    try? FileManager.default.removeItem(at: installURL)
+    // Determine if installing to current directory
+    let isCurrentDirectory = path == "." || path == "current"
+    let installURL: URL
+
+    if isCurrentDirectory {
+      installURL = URL(fileURLWithPath: FileManager.default.currentDirectoryPath)
+
+      // Verify the current directory is in the expected location
+      let currentPath = installURL.path
+      let expectedPattern = ".\(tool.rawValue)/skills"
+
+      guard currentPath.contains(expectedPattern) else {
+        print("Error: Current directory is not in the expected location.")
+        print("Expected to be inside: ~/.\(tool.rawValue)/skills/")
+        print("Current directory: \(currentPath)")
+        throw ExitCode.failure
+      }
+
+      // Ask for confirmation
+      print("You are about to install into the current directory:")
+      print("  \(currentPath)")
+      print("\nThis will merge new skills with existing ones without removing current files.")
+      print("Continue? (yes/no): ", terminator: "")
+
+      guard let response = readLine()?.lowercased(),
+            response == "yes" || response == "y" else {
+        print("Installation cancelled.")
+        throw ExitCode.success
+      }
+    } else {
+      installURL = URL(fileURLWithPath: path ?? tool.defaultInstallPath.path)
+    }
+
+    // Always merge - never remove existing files
     try FileManager.default.unzipItem(at: zipURL, to: installURL)
-    print("Installed skills for \(tool.rawValue) into \(installURL.path)")
+
+    if isCurrentDirectory {
+      print("Successfully merged skills into \(installURL.path)")
+    } else {
+      print("Installed and merged skills for \(tool.rawValue) into \(installURL.path)")
+    }
   }
 }