feat: add auto_record_calendar setting (FR-CAL)

src-tauri/src/models.rs

@@ -285,6 +285,12 @@ pub struct Settings {
     /// Outlook ever generated) on every launch.
     #[serde(default)]
     pub pst_import_range_days: Option<u32>,
+    /// Auto-start recording when a calendar event begins while the app is open
+    /// (FR-CAL, opt-in). OFF by default. No background timer runs for this: the
+    /// UI arms a single one-shot timer to the next event while the app is open
+    /// and disarms it on close, so idle resource use stays at zero (NFR-RES-1).
+    #[serde(default)]
+    pub auto_record_calendar: bool,
     // Microsoft Graph calendar source (M4.4, T8.9, ADR-0008, FR-CAL-6). Opt-in,
     // explicit consent via OAuth PKCE — off by default. The credential ref
     // points into the OS credential store; the token itself never lives here.