Split has_content test into three cases per reviewer request

Separate tests for empty/whitespace/non-blank input so a regression
points at the exact case that broke instead of a single bundled test.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XJJQb2DWZZwQ1yPiaAQQoY

crates/feeds/src/lib.rs

@@ -74,12 +74,22 @@ fn estimate_read_seconds(text: &str) -> u32 {
 mod tests {
     use super::*;
 
-    /// A blank or whitespace-only feed title should be treated the same as
-    /// a missing one, not surfaced as an empty string in the UI.
+    /// An empty feed title should be treated the same as a missing one.
     #[test]
-    fn has_content_rejects_blank_strings() {
+    fn has_content_rejects_empty_string() {
         assert!(!has_content(""));
+    }
+
+    /// A whitespace-only feed title should be treated the same as a
+    /// missing one, not surfaced as a blank-looking name in the UI.
+    #[test]
+    fn has_content_rejects_whitespace_only_string() {
         assert!(!has_content("   \n\t"));
+    }
+
+    /// A real title is accepted as-is.
+    #[test]
+    fn has_content_accepts_non_blank_string() {
         assert!(has_content("Rust Blog"));
     }
 }