The repeat rules are pinned by the shared fixture

daily/weekly/monthly/yearly was written out in the server (REMINDER_RECURRENCES),
the core (recur::RECURRENCES), the web editor's <option>s and Android's picker,
with nothing holding them together. grammar.json now has a recurrences list; the
server, core and web suites each check theirs against it, and the web's options
come from notes/recurrence.ts rather than the template. Android's picker pins the
list by hand with its localised labels, as it does the tint: its JVM tests do not
read the fixture.

DRY pass #2, batch 3 (#5372).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

core/src/local/recur.rs

@@ -74,6 +74,19 @@ mod tests {
     use super::*;
     use chrono::TimeZone;
 
+    #[test]
+    fn the_rules_are_the_shared_fixtures() {
+        let fixture: serde_json::Value =
+            serde_json::from_str(include_str!("../../testdata/grammar.json")).expect("parses");
+        let want: Vec<&str> = fixture["recurrences"]
+            .as_array()
+            .expect("a list")
+            .iter()
+            .map(|r| r.as_str().expect("a string"))
+            .collect();
+        assert_eq!(RECURRENCES.to_vec(), want);
+    }
+
     fn utc(y: i32, m: u32, d: u32, h: u32, min: u32) -> DateTime<Utc> {
         Utc.with_ymd_and_hms(y, m, d, h, min, 0).unwrap()
     }