feat(life_capture): strip quoted replies from email bodies

src/openhuman/life_capture/quote_strip.rs

@@ -1 +1,57 @@
-// Filled in by later tasks.
+use once_cell::sync::Lazy;
+use regex::Regex;
+
+static ON_DATE_WROTE: Lazy<Regex> = Lazy::new(|| {
+    // "On <date>, <name> <email|>(?) wrote:" — match start of any line.
+    Regex::new(r"(?m)^On .{1,200}\bwrote:\s*$").unwrap()
+});
+
+static OUTLOOK_SEP: Lazy<Regex> = Lazy::new(|| {
+    Regex::new(r"(?m)^-{3,}\s*Original Message\s*-{3,}\s*$").unwrap()
+});
+
+/// Returns only the new content of an email body — drops everything from the
+/// first quoted-reply marker onward, plus any line that begins with '>'.
+pub fn strip_quoted_reply(body: &str) -> String {
+    // Cut at the earliest of the two marker types.
+    let mut cut: Option<usize> = None;
+    for re in [&*ON_DATE_WROTE, &*OUTLOOK_SEP] {
+        if let Some(m) = re.find(body) {
+            cut = Some(cut.map_or(m.start(), |c| c.min(m.start())));
+        }
+    }
+    let head = if let Some(idx) = cut { &body[..idx] } else { body };
+
+    // Drop any line starting with '>'.
+    let kept: Vec<&str> = head.lines().filter(|l| !l.trim_start().starts_with('>')).collect();
+    kept.join("\n").trim().to_string()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn strips_on_date_wrote_block_and_below() {
+        let input = "Quick reply.\n\nOn Mon, Apr 21, 2026 at 9:14 AM, Sarah <sarah@x> wrote:\n> earlier text\n>> deeper\n";
+        assert_eq!(strip_quoted_reply(input), "Quick reply.");
+    }
+
+    #[test]
+    fn strips_lines_starting_with_gt() {
+        let input = "new thought\n> old thought\n> > older\nnewer\n";
+        assert_eq!(strip_quoted_reply(input), "new thought\nnewer");
+    }
+
+    #[test]
+    fn strips_outlook_original_message_separator() {
+        let input = "reply text\n\n-----Original Message-----\nFrom: a@b\nTo: c@d\nSubject: ...\nbody";
+        assert_eq!(strip_quoted_reply(input), "reply text");
+    }
+
+    #[test]
+    fn passthrough_when_no_quote_found() {
+        let s = "single paragraph no markers";
+        assert_eq!(strip_quoted_reply(s), s);
+    }
+}