fix(http): send market orders as FrontendMarket, not GTC

src/hypercore/http.rs

@@ -1193,7 +1193,7 @@ impl Client {
                 sz: size,
                 reduce_only: false,
                 order_type: OrderTypePlacement::Limit {
-                    tif: TimeInForce::Gtc,
+                    tif: TimeInForce::FrontendMarket,
                 },
                 cloid: Default::default(),
             }],

src/hypercore/mod.rs

@@ -714,7 +714,10 @@ impl PriceTick {
     /// See the PriceTick documentation for calculation details.
     pub fn tick_for(&self, price: Decimal) -> Option<Decimal> {
         let sig_figs = price.log10();
-        let sig_figs_n = sig_figs.ceil().to_i32()? as i64;
+        // Integer digits = floor(log10(price)) + 1. ceil() and floor+1 agree
+        // except when log10(price) is exact (price a power of ten), where
+        // ceil() undercounts by one and yields a tick ten times too fine.
+        let sig_figs_n = sig_figs.floor().to_i32()? as i64 + 1;
         let decimals = 5_i64 - sig_figs_n;
         let max_decimals = decimals.clamp(0, self.max_decimals);
         Some(Decimal::TEN.powi(-max_decimals))
@@ -1155,6 +1158,26 @@ mod tick_tests {
             );
         }
     }
+
+    #[test]
+    fn power_of_ten_prices_keep_five_sig_figs() {
+        // Prices that are exact powers of ten exercise the difference
+        // between ceil(log10) and floor(log10) + 1. The latter is the
+        // documented algorithm; the former undercounts the integer digits
+        // by one and yields a tick ten times too fine.
+        let table = PriceTick::for_perp(0); // max_decimals = 6
+        for (price, expected_tick) in [
+            (dec!(1000), dec!(0.1)),
+            (dec!(100), dec!(0.01)),
+            (dec!(10), dec!(0.001)),
+            (dec!(1), dec!(0.0001)),
+        ] {
+            assert_eq!(table.tick_for(price), Some(expected_tick), "{price}");
+        }
+
+        let spot = PriceTick::for_spot(0); // max_decimals = 8
+        assert_eq!(spot.tick_for(dec!(1000)), Some(dec!(0.1)));
+    }
 }
 
 /// Spot token on HyperCore.