feat: dictation segmentation on blank lines

src/segment.rs

@@ -1 +1,20 @@
-// implemented in a later task
+/// Split a dictation into Befund segments on Markdown paragraph
+/// breaks (one or more blank lines). Trims each segment; drops empties.
+pub fn split_segments(dictation: &str) -> Vec<String> {
+    let mut segments = Vec::new();
+    let mut current: Vec<&str> = Vec::new();
+    for line in dictation.lines() {
+        if line.trim().is_empty() {
+            if !current.is_empty() {
+                segments.push(current.join("\n").trim().to_string());
+                current.clear();
+            }
+        } else {
+            current.push(line);
+        }
+    }
+    if !current.is_empty() {
+        segments.push(current.join("\n").trim().to_string());
+    }
+    segments.into_iter().filter(|s| !s.is_empty()).collect()
+}

tests/segment_tests.rs

@@ -0,0 +1,22 @@
+use alpha_id::segment::split_segments;
+
+#[test]
+fn splits_on_blank_lines() {
+    let d = "Befund eins\nmit Zeile zwei\n\nBefund zwei\n\n\nBefund drei\n";
+    let segs = split_segments(d);
+    assert_eq!(segs, vec![
+        "Befund eins\nmit Zeile zwei".to_string(),
+        "Befund zwei".to_string(),
+        "Befund drei".to_string(),
+    ]);
+}
+
+#[test]
+fn single_segment_when_no_blank_line() {
+    assert_eq!(split_segments("nur ein Befund"), vec!["nur ein Befund".to_string()]);
+}
+
+#[test]
+fn empty_input_yields_no_segments() {
+    assert!(split_segments("   \n\n").is_empty());
+}