Merge branch 'develop'

Includes security fixes, bug fixes, and code quality refactors:
- Fix command injection in DNFPackageManager (system() multi-arg form)
- Fix backup_resursively! typo (latent NoMethodError)
- Add error handling to DNFPackageManager (CommandFailed + run_dnf!)
- Split file.rb monolith into per-class files
- Extract DryRun concern (SRP), narrow BasicFile interface (ISP)
- Extract register_keyword DSL helper (DRY)
- Replace ObjectSpace scan with inherited-hook class registry
- Defer Options.parse! and Config.load! to application entry point
- Add Justfiles to all example directories

1 files changed, 16 insertions, 5 deletions

diff --git a/lib/config.rb b/lib/config.rb
index 2a13ae0..fa43c4f 100644
--- a/lib/config.rb
+++ b/lib/config.rb
@@ -8,12 +8,23 @@ end
 module RCM
   # Configuration — config.toml is optional. If the toml gem is not installed
   # or no config.toml exists, config() will raise a helpful error when called.
+  #
+  # Config is not loaded at module load time. Call Config.load! once at the
+  # application entry point (e.g. from configure) before calling config().
+  # Tests that don't use config() don't need config.toml at all.
   module Config
-    @@config = if TOML_AVAILABLE && File.exist?('config.toml')
-                 TOML.load_file('config.toml')
-               else
-                 {}
-               end
+    @@config = {}
+
+    # Load (or reload) config.toml from the current working directory.
+    # Falls back to an empty hash when the toml gem is unavailable or the
+    # file does not exist, so callers that never invoke config() are unaffected.
+    def self.load!
+      @@config = if TOML_AVAILABLE && ::File.exist?('config.toml')
+                   TOML.load_file('config.toml')
+                 else
+                   {}
+                 end
+    end
 
     def config(key)
       raise "No such config key: #{key}" unless @@config.key?(key)