fix(sentiment): treat an empty MSN response as no votes, not a parse error

MSN SentimentBrowser returns `[]` for every IDX ticker checked live
(BBCA, BBRI, TLKM), so `stocks sentiment` always failed with
PARSEERROR. Return empty statistics instead; the table prints a
one-line notice and JSON gets `"statistics": []` with exit 0.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ld3fDSDiBzAaQvgZJX5NKM

src/api/msn/map.rs

@@ -460,9 +460,15 @@ pub(super) fn parse_sentiment(
     symbol: &str,
     raw: &[RawSentiment],
 ) -> Result<SentimentData, IdxError> {
-    let item = raw
-        .first()
-        .ok_or_else(|| IdxError::ParseError("no sentiment data".into()))?;
+    // MSN answers `[]` for tickers nobody has voted on (all IDX names as of
+    // 2026-10). That is "no votes", not a malformed response.
+    let Some(item) = raw.first() else {
+        let ticker = ticker_from_symbol(symbol).unwrap_or_default();
+        return Ok(SentimentData {
+            symbol: normalized_symbol(symbol, &ticker),
+            statistics: Vec::new(),
+        });
+    };
     let stats = item
         .sentiment_statistics
         .as_ref()
@@ -929,6 +935,13 @@ mod tests {
         );
     }
 
+    #[test]
+    fn empty_sentiment_response_is_empty_data_not_an_error() {
+        let sentiment = parse_sentiment("BBCA", &[]).expect("empty sentiment is valid");
+        assert_eq!(sentiment.symbol, "BBCA.JK");
+        assert!(sentiment.statistics.is_empty());
+    }
+
     #[test]
     fn parses_msn_chart_price_only_fixture_as_synthetic_ohlc() {
         let raw: Vec<RawChartResponse> = serde_json::from_str(include_str!(

src/output/table.rs

@@ -768,6 +768,10 @@ pub fn print_earnings(report: &EarningsReport) -> Result<(), IdxError> {
 }
 
 pub fn print_sentiment(data: &SentimentData) -> Result<(), IdxError> {
+    if data.statistics.is_empty() {
+        println!("No sentiment votes for {}.", data.symbol);
+        return Ok(());
+    }
     let mut table = Table::new();
     table
         .load_preset(UTF8_FULL)