desktop: fix a retention test that raced the wall clock

`a_note_exactly_at_the_boundary_survives` stamped a note 30 days ago and then
asked the sweep — which reads `now` microseconds later — whether it was
strictly older than 30 days. It was, by those microseconds. The assertion was
wrong, not the code: an exact tie isn't observable against a wall clock.

Now stamps a note with a minute of its window still to run, which is the
property actually worth pinning: the comparison is strictly-older, so a note
inside the window is kept.

Also rewrote the row scan as plain statements. The `filter_map` over
`query_map` swallowed real rusqlite errors through `.ok()?` on the way to
skipping unparseable timestamps — the two cases deserve different treatment,
and only the second should be silent.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SreJkbxB4gx8pPsu8QbLPi

desktop/src-tauri/src/sync/pull.rs

@@ -533,6 +533,11 @@ mod tests {
         conn.query_row(sql, [], |r| r.get(0)).expect("count")
     }
 
+    fn trash_stamp(conn: &Connection, id: &str) -> Option<String> {
+        let sql = "SELECT trashed_at FROM notes WHERE id = ?1";
+        conn.query_row(sql, [id], |r| r.get(0)).expect("stamp")
+    }
+
     #[test]
     fn applies_a_note_and_advances_the_cursor() {
         let conn = db();
@@ -582,12 +587,8 @@ mod tests {
         trashed.trashed = true;
         trashed.deleted_at = Some("2026-06-01T09:30:00+00:00".into());
         apply_page(&conn, &page(vec![trashed], vec![], 1)).expect("apply");
-        let stamped: String = conn
-            .query_row("SELECT trashed_at FROM notes WHERE id = 'n1'", [], |r| {
-                r.get(0)
-            })
-            .expect("trashed_at");
-        assert_eq!(stamped, "2026-06-01T09:30:00+00:00");
+        let stamped = trash_stamp(&conn, "n1");
+        assert_eq!(stamped.as_deref(), Some("2026-06-01T09:30:00+00:00"));
     }
 
     #[test]
@@ -598,12 +599,8 @@ mod tests {
         trashed.deleted_at = Some("2026-06-01T09:30:00+00:00".into());
         apply_page(&conn, &page(vec![trashed], vec![], 1)).expect("apply");
         apply_page(&conn, &page(vec![note("n1", 2)], vec![], 2)).expect("apply");
-        let stamped: Option<String> = conn
-            .query_row("SELECT trashed_at FROM notes WHERE id = 'n1'", [], |r| {
-                r.get(0)
-            })
-            .expect("trashed_at");
-        assert_eq!(stamped, None, "an untrashed note must carry no trash stamp");
+        let stamped = trash_stamp(&conn, "n1");
+        assert_eq!(stamped, None, "an untrashed note keeps no trash stamp");
     }
 
     #[test]
@@ -615,11 +612,7 @@ mod tests {
         trashed.trashed = true;
         trashed.deleted_at = None;
         apply_page(&conn, &page(vec![trashed], vec![], 1)).expect("apply");
-        let stamped: Option<String> = conn
-            .query_row("SELECT trashed_at FROM notes WHERE id = 'n1'", [], |r| {
-                r.get(0)
-            })
-            .expect("trashed_at");
+        let stamped = trash_stamp(&conn, "n1");
         assert_eq!(stamped.as_deref(), Some("2026-07-26T00:00:00.000Z"));
     }