feat(calendar): one-shot PST auto-sync on launch

Mirrors the existing sync-job-resume pattern right above it: runs once
at startup if pst_auto_sync is on and a path is remembered, no idle
timer (NFR-RES-1). Re-import is dedup'd by (source, raw_uid), so this
just catches up on new/changed events since last launch.

src-tauri/src/lib.rs

@@ -161,6 +161,22 @@ pub fn run() {
                 if commands::load_settings().sync_enabled {
                     commands::pump_sync(&startup_app, store.as_ref()).await;
                 }
+
+                // Re-import the last .pst path if the user opted into auto-sync
+                // (T6.2). One-shot on startup, same as the sync-job resume above
+                // — no idle timer (NFR-RES-1). Re-import is dedup'd by
+                // (source, raw_uid), so this just catches up on new/changed events.
+                let pst_settings = commands::load_settings();
+                if pst_settings.pst_auto_sync {
+                    if let Some(path) = pst_settings.pst_last_path {
+                        if let Err(e) =
+                            commands::import_pst_core(&startup_app, store.as_ref(), path, None)
+                                .await
+                        {
+                            tracing::warn!("startup PST auto-sync failed: {e:?}");
+                        }
+                    }
+                }
             });
             Ok(())
         })