Add Month memory filter span

src/memories.rs

@@ -17,6 +17,7 @@ use crate::state::AppState;
 pub enum MemoriesSpan {
     Day,
     Week,
+    Month,
 }
 
 #[derive(Deserialize)]
@@ -147,6 +148,7 @@ fn is_memories_match(
     match span {
         MemoriesSpan::Day => same_month_day_any_year(file_date, today),
         MemoriesSpan::Week => same_week_any_year(file_date, today),
+        MemoriesSpan::Month => same_month_any_year(file_date, today),
     }
 }
 
@@ -162,6 +164,11 @@ fn same_week_any_year(a: NaiveDate, b: NaiveDate) -> bool {
     a.iso_week().week().eq(&b.iso_week().week())
 }
 
+// Match same month (ignoring day and year)
+fn same_month_any_year(a: NaiveDate, b: NaiveDate) -> bool {
+    a.month() == b.month()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -189,6 +196,31 @@ mod tests {
         assert!(same_week_any_year(a, b));
     }
 
+    #[test]
+    fn test_same_month_any_year() {
+        let today = NaiveDate::from_ymd_opt(2025, 8, 8).unwrap();
+        // Same month, different year and day - should match
+        assert!(same_month_any_year(
+            NaiveDate::from_ymd_opt(2019, 8, 1).unwrap(),
+            today
+        ));
+        // Different month - should not match
+        assert!(!same_month_any_year(
+            NaiveDate::from_ymd_opt(2019, 9, 8).unwrap(),
+            today
+        ));
+        // Same month, same year, different day - should match
+        assert!(same_month_any_year(
+            NaiveDate::from_ymd_opt(2025, 8, 15).unwrap(),
+            today
+        ));
+        // Test January vs December
+        assert!(!same_month_any_year(
+            NaiveDate::from_ymd_opt(2020, 1, 1).unwrap(),
+            NaiveDate::from_ymd_opt(2025, 12, 31).unwrap()
+        ));
+    }
+
     #[test]
     fn test_years_back_limit() {
         let today = NaiveDate::from_ymd_opt(2025, 8, 8).unwrap();