yoda: phase 2 — customizable toolbar (settings toggles per button)

Phase 1 shipped a fixed 6-button toolbar. Phase 2 moves visibility to
the config so users pick which buttons appear.

Config (config.rs):
- new ToolbarItems struct (CosmicConfigEntry) with one bool per button
- Config.toolbar: ToolbarItems, default = 'minimal 6' set from phase 1
  (new_folder, rename, delete, cut, copy, paste) + 5 extras off
  (new_file, reload, toggle_show_hidden, open_terminal, location_up)

Rendering (view()):
- iterate through self.config.toolbar fields in fixed logical order
  (location → create/edit → clipboard → view toggles)
- dividers inserted only between non-empty groups
- whole toolbar hidden if every button is off (no empty container)

Settings page (settings()):
- new 'Toolbar' section with one toggler per button, wired through
  Message::SetToolbar(ToolbarItems) which persists via config_set!

i18n (en + fr):
- added 'toolbar' + 'parent-directory' strings
- reused existing new-folder / new-file / rename / delete / cut / copy /
  paste / reload-folder / show-hidden-files / open-in-terminal

All actions dispatch through Action::message so keybindings and toolbar
share one code path.

src/config.rs

@@ -172,6 +172,10 @@ pub struct Config {
     pub show_details: bool,
     pub show_recents: bool,
     pub tab: TabConfig,
+    /// Yoda: Dolphin-style quick actions toolbar under the tab bar.
+    /// Each bool toggles one button; order in the UI is fixed (logical
+    /// grouping file-ops then clipboard then view toggles).
+    pub toolbar: ToolbarItems,
     pub type_to_search: TypeToSearch,
 }
 
@@ -236,11 +240,48 @@ impl Default for Config {
             show_details: false,
             show_recents: true,
             tab: TabConfig::default(),
+            toolbar: ToolbarItems::default(),
             type_to_search: TypeToSearch::Recursive,
         }
     }
 }
 
+/// Yoda: visibility toggles for each quick-action toolbar button.
+/// Default = the original "minimal 6" set (new_folder, rename, delete,
+/// cut, copy, paste). Other items default to false so users opt in.
+#[derive(Clone, Copy, CosmicConfigEntry, Debug, Deserialize, Eq, PartialEq, Serialize)]
+pub struct ToolbarItems {
+    pub new_folder: bool,
+    pub new_file: bool,
+    pub rename: bool,
+    pub delete: bool,
+    pub cut: bool,
+    pub copy: bool,
+    pub paste: bool,
+    pub reload: bool,
+    pub toggle_show_hidden: bool,
+    pub open_terminal: bool,
+    pub location_up: bool,
+}
+
+impl Default for ToolbarItems {
+    fn default() -> Self {
+        Self {
+            new_folder: true,
+            new_file: false,
+            rename: true,
+            delete: true,
+            cut: true,
+            copy: true,
+            paste: true,
+            reload: false,
+            toggle_show_hidden: false,
+            open_terminal: false,
+            location_up: false,
+        }
+    }
+}
+
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, CosmicConfigEntry, Deserialize, Serialize)]
 #[serde(default)]
 pub struct DesktopConfig {