insight-chat: get_sms_messages tool now honors days_radius

The agentic tool definition advertised a days_radius parameter but
sms_client::fetch_messages_for_contact was hardcoded to ±4 days,
silently ignoring whatever value the LLM chose. Plumb the parameter
through; default 4 retained at the tool level for back-compat.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ai/insight_generator.rs

@@ -983,7 +983,7 @@ impl InsightGenerator {
             // Step 1: Get FULL immediate temporal context (±4 days, ALL messages)
             let immediate_messages = self
                 .sms_client
-                .fetch_messages_for_contact(contact.as_deref(), timestamp)
+                .fetch_messages_for_contact(contact.as_deref(), timestamp, 4)
                 .await
                 .unwrap_or_else(|e| {
                     log::error!("Failed to fetch immediate messages: {}", e);
@@ -1129,7 +1129,7 @@ impl InsightGenerator {
             log::info!("Using traditional time-based message retrieval (±4 days)");
             let sms_messages = self
                 .sms_client
-                .fetch_messages_for_contact(contact.as_deref(), timestamp)
+                .fetch_messages_for_contact(contact.as_deref(), timestamp, 4)
                 .await
                 .unwrap_or_else(|e| {
                     log::error!("Failed to fetch SMS messages: {}", e);
@@ -1835,7 +1835,7 @@ Return ONLY the summary, nothing else."#,
 
         match self
             .sms_client
-            .fetch_messages_for_contact(contact.as_deref(), timestamp)
+            .fetch_messages_for_contact(contact.as_deref(), timestamp, days_radius)
             .await
         {
             Ok(messages) if !messages.is_empty() => {

src/ai/sms_client.rs

@@ -20,31 +20,35 @@ impl SmsApiClient {
         }
     }
 
-    /// Fetch messages for a specific contact within ±4 days of the given timestamp
-    /// Falls back to all contacts if no messages found for the specific contact
-    /// Messages are sorted by proximity to the center timestamp
+    /// Compute a `[start, end]` unix-second window of `2 * radius_days`
+    /// centered on `center_ts`. `radius_days < 1` is clamped to 1 to avoid
+    /// degenerate zero-width windows.
+    pub(crate) fn window_for_radius(center_ts: i64, radius_days: i64) -> (i64, i64) {
+        let r = radius_days.max(1);
+        let span = r * 86400;
+        (center_ts - span, center_ts + span)
+    }
+
+    /// Fetch messages for a specific contact within ±`radius_days` of the
+    /// given timestamp. Falls back to all contacts when no messages found
+    /// for the named contact. Sorted by proximity to the center timestamp.
     pub async fn fetch_messages_for_contact(
         &self,
         contact: Option<&str>,
         center_timestamp: i64,
+        radius_days: i64,
     ) -> Result<Vec<SmsMessage>> {
-        use chrono::Duration;
+        let (start_ts, end_ts) = Self::window_for_radius(center_timestamp, radius_days);
 
-        // Calculate ±4 days range around the center timestamp
         let center_dt = chrono::DateTime::from_timestamp(center_timestamp, 0)
             .ok_or_else(|| anyhow::anyhow!("Invalid timestamp"))?;
 
-        let start_dt = center_dt - Duration::days(4);
-        let end_dt = center_dt + Duration::days(4);
-
-        let start_ts = start_dt.timestamp();
-        let end_ts = end_dt.timestamp();
-
         // If contact specified, try fetching for that contact first
         if let Some(contact_name) = contact {
             log::info!(
-                "Fetching SMS for contact: {} (±4 days from {})",
+                "Fetching SMS for contact: {} (±{} days from {})",
                 contact_name,
+                radius_days.max(1),
                 center_dt.format("%Y-%m-%d %H:%M:%S")
             );
             let messages = self
@@ -68,7 +72,8 @@ impl SmsApiClient {
 
         // Fallback to all contacts
         log::info!(
-            "Fetching all SMS messages (±4 days from {})",
+            "Fetching all SMS messages (±{} days from {})",
+            radius_days.max(1),
             center_dt.format("%Y-%m-%d %H:%M:%S")
         );
         self.fetch_messages(start_ts, end_ts, None, Some(center_timestamp))
@@ -379,3 +384,23 @@ struct SmsSearchResponse {
     #[serde(default)]
     search_method: String,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn window_for_radius_produces_2n_day_span() {
+        let center: i64 = 1_700_000_000;
+        let (start, end) = SmsApiClient::window_for_radius(center, 7);
+        assert_eq!(end - start, 14 * 86400);
+        assert_eq!(start + 7 * 86400, center);
+        assert_eq!(end - 7 * 86400, center);
+    }
+
+    #[test]
+    fn window_for_radius_clamps_negative_to_one() {
+        let (start, end) = SmsApiClient::window_for_radius(100_000, 0);
+        assert_eq!(end - start, 2 * 86400);
+    }
+}