make rcm usable as a gem from any directory, fix bugs and tests

- Add lib/rcm.rb entry point and bin/rcm CLI executable
- Update gemspec: v0.1.0, proper files list, executables, runtime deps
- Support standalone arg parsing and --hosts filtering in options
- Fix inverted logic and typo in FileBackup#different? (== vs !=, cecksum_b)
- Fix unqualified File.directory? resolving to RCM::File in Directory
- Fix test_chown assertions running before evaluate! creates files
- Add setup to file tests to prevent order-dependent failures

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

2 files changed, 18 insertions, 12 deletions

diff --git a/test/lib/dslkeywords/file_test.rb b/test/lib/dslkeywords/file_test.rb
index 35a0f21..a290627 100644
--- a/test/lib/dslkeywords/file_test.rb
+++ b/test/lib/dslkeywords/file_test.rb
@@ -12,6 +12,12 @@ class RCMFileTest < Minitest::Test
     FileUtils.rm_r(DIR_PATH) if File.directory?(DIR_PATH)
   end
 
+  # Clean up shared temp file between tests to prevent order-dependent failures
+  def setup
+    File.unlink(FILE_PATH) if File.file?(FILE_PATH)
+    FileUtils.rm_r(DIR_PATH) if File.directory?(DIR_PATH)
+  end
+
   def test_create_file_from_string
     text = 'Hello World!'
     configure_from_scratch do
diff --git a/test/lib/dslkeywords/mode_test.rb b/test/lib/dslkeywords/mode_test.rb
index a4bf099..6e93bde 100644
--- a/test/lib/dslkeywords/mode_test.rb
+++ b/test/lib/dslkeywords/mode_test.rb
@@ -48,12 +48,12 @@ class RCMModeTest < Minitest::Test
   end
 
   def test_chown
-    configure_from_scratch do
-      # Well, test only makes sense that it doesn't throw any exception, as test
-      # can't change files to other owners as test will likely run as non-root.
-      user_name = Etc.getlogin
-      group_name = Etc.getgrgid(Process.gid).name
+    # Test only verifies no exception is thrown, as test runs as non-root
+    # and can't change files to other owners.
+    user_name = Etc.getlogin
+    group_name = Etc.getgrgid(Process.gid).name
 
+    configure_from_scratch do
       touch FILE1_PATH do
         owner user_name
         group group_name
@@ -62,14 +62,14 @@ class RCMModeTest < Minitest::Test
         owner user_name
         group group_name
       end
+    end
 
-      stat = File.stat(FILE1_PATH)
-      assert_equal user_name, Etc.getpwuid(stat.uid)
-      assert_equal group_name, Etc.getgrgid(stat.gid)
+    stat = File.stat(FILE1_PATH)
+    assert_equal user_name, Etc.getpwuid(stat.uid).name
+    assert_equal group_name, Etc.getgrgid(stat.gid).name
 
-      stat = File.stat(DIR_PATH)
-      assert_equal user_name, Etc.getpwuid(stat.uid)
-      assert_equal group_name, Etc.getgrgid(stat.gid)
-    end
+    stat = File.stat(DIR_PATH)
+    assert_equal user_name, Etc.getpwuid(stat.uid).name
+    assert_equal group_name, Etc.getgrgid(stat.gid).name
   end
 end