Add Interface Scale setting to zoom the whole app (80-200%)

src-tauri/capabilities/desktop.json

@@ -6,6 +6,7 @@
   "windows": ["main"],
   "permissions": [
     "updater:default",
-    "window-state:default"
+    "window-state:default",
+    "core:webview:allow-set-webview-zoom"
   ]
 }

src-tauri/src/commands.rs

@@ -103,6 +103,14 @@ pub fn set_line_height(state: State<'_, AppState>, height: f64) -> Result<(), St
     Ok(())
 }
 
+#[tauri::command]
+pub fn set_ui_scale(state: State<'_, AppState>, scale: f64) -> Result<(), String> {
+    let mut config = state.config.lock().map_err(|e| e.to_string())?;
+    config.ui_scale = Some(scale);
+    save_app_config(&config)?;
+    Ok(())
+}
+
 // ── Notebooks ──
 
 #[tauri::command]

src-tauri/src/lib.rs

@@ -103,6 +103,7 @@ pub fn run() {
             commands::set_font_size,
             commands::set_font_family,
             commands::set_line_height,
+            commands::set_ui_scale,
             commands::get_notebooks,
             commands::count_root_notes,
             commands::create_notebook,

src-tauri/src/types.rs

@@ -70,6 +70,8 @@ pub struct AppConfig {
     #[serde(default)]
     pub line_height: Option<f64>,
     #[serde(default)]
+    pub ui_scale: Option<f64>,
+    #[serde(default)]
     pub compact_notes: bool,
     #[serde(default)]
     pub time_format: String,
@@ -167,6 +169,7 @@ impl Default for AppConfig {
             font_size: None,
             font_family: None,
             line_height: None,
+            ui_scale: None,
             compact_notes: false,
             time_format: "relative".to_string(),
             gpu_acceleration: true,