M2: terminal UI (ratatui)

- layout: header, top menu (quicklook, cpu, mem, swap, load), left sidebar,
  process list and alert footer
- decorations/colors, bars, per-plugin render implementations
- hotkeys: quit, help, modes, sorting, cursor, nice, kill, filters, toggles
- TestBackend layout test

crates/glances-plugins/src/engine.rs

@@ -54,9 +54,20 @@ impl Engine {
         let mut engine = Self { args, config, runtime, plugins };
         engine.apply_plugin_options();
         engine.apply_process_options();
+        engine.sync_enabled();
         engine
     }
 
+    /// Refresh the runtime set of enabled plugins.
+    pub fn sync_enabled(&mut self) {
+        self.runtime.enabled_plugins = self
+            .plugins
+            .iter()
+            .filter(|(_, plugin)| plugin.is_enabled())
+            .map(|(name, _)| name.clone())
+            .collect();
+    }
+
     fn apply_plugin_options(&mut self) {
         // Disable plugins from the configuration file.
         for section in self.config.sections() {