Make file writable before applying strip (#12)

Fixes elixir-desktop/desktop-example-app#31

The strip command modifies files in-place and fails with 'Permission denied'
when files (e.g. .so NIF libraries) have read-only permissions. Ensure the
file is writable with File.chmod! before running strip, matching the pattern
already used in file_replace/3.

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Dominic Letz <dominicletz@users.noreply.github.com>

Author: dominicletz

lib/tooling.ex

@@ -76,11 +76,17 @@ defmodule Desktop.Deployment.Tooling do
     is_binary = extname == ""
     is_library = Regex.match?(~r/\.(so|dylib|smp)($|\.)/, extname)
 
-    cond do
-      os() == MacOS and is_library -> cmd!("strip", ["-x", "-S", file])
-      os() == MacOS and is_binary -> cmd!("strip", ["-u", "-r", file])
-      is_binary || is_library -> cmd!("strip", ["-s", file])
-      true -> :ok
+    strip_args =
+      cond do
+        os() == MacOS and is_library -> ["-x", "-S"]
+        os() == MacOS and is_binary -> ["-u", "-r"]
+        is_binary || is_library -> ["-s"]
+        true -> nil
+      end
+
+    if strip_args do
+      File.chmod!(file, Bitwise.bor(File.lstat!(file).mode, 0o200))
+      cmd!("strip", strip_args ++ [file])
     end
 
     file