fix(workout-builder): defer TextInput updates to onBlur using local state

src/features/workout-builder/screens/BuilderScreen.tsx

@@ -16,6 +16,7 @@ export function BuilderScreen() {
   const navigation = useNavigation<NativeStackNavigationProp<RootStackParamList>>();
   const { poolLength: defaultPoolLength } = useSettings();
   const [poolLength, setPoolLength] = useState(defaultPoolLength);
+  const [fieldValues, setFieldValues] = useState<Record<string, string>>({});
   const {
     sets,
     workoutName,
@@ -124,8 +125,19 @@ export function BuilderScreen() {
                 <Text className="text-xs font-medium text-slate-500 mb-1">{t("distanceM")}</Text>
                 <TextInput
                   keyboardType="numeric"
-                  value={String(set.distancePerRep)}
+                  value={fieldValues[`${index}-distance`] ?? String(set.distancePerRep)}
-                  onChangeText={(val) => updateSet(index, { distancePerRep: Number(val) || 0 })}
+                  onChangeText={(val) => setFieldValues((prev) => ({ ...prev, [`${index}-distance`]: val }))}
+                  onBlur={() => {
+                    const num = Number(fieldValues[`${index}-distance`] ?? set.distancePerRep);
+                    updateSet(index, { distancePerRep: isNaN(num) || num < poolLength ? poolLength : num });
+                    setFieldValues((prev) => {
+                      const next = { ...prev };
+                      delete next[`${index}-distance`];
+                      return next;
+                    });
+                  }}
+                  placeholder={String(poolLength)}
+                  placeholderTextColor="#94a3b8"
                   className="bg-white border border-slate-300 rounded-lg px-3 py-2 text-slate-900"
                 />
               </View>
@@ -133,8 +145,19 @@ export function BuilderScreen() {
                 <Text className="text-xs font-medium text-slate-500 mb-1">{t("reps")}</Text>
                 <TextInput
                   keyboardType="numeric"
-                  value={String(set.repCount)}
+                  value={fieldValues[`${index}-rep`] ?? String(set.repCount)}
-                  onChangeText={(val) => updateSet(index, { repCount: Number(val) || 1 })}
+                  onChangeText={(val) => setFieldValues((prev) => ({ ...prev, [`${index}-rep`]: val }))}
+                  onBlur={() => {
+                    const num = Number(fieldValues[`${index}-rep`] ?? set.repCount);
+                    updateSet(index, { repCount: isNaN(num) || num < 1 ? 1 : num });
+                    setFieldValues((prev) => {
+                      const next = { ...prev };
+                      delete next[`${index}-rep`];
+                      return next;
+                    });
+                  }}
+                  placeholder="1"
+                  placeholderTextColor="#94a3b8"
                   className="bg-white border border-slate-300 rounded-lg px-3 py-2 text-slate-900"
                 />
               </View>
@@ -142,8 +165,19 @@ export function BuilderScreen() {
                 <Text className="text-xs font-medium text-slate-500 mb-1">{t("restS")}</Text>
                 <TextInput
                   keyboardType="numeric"
-                  value={String(set.restDuration)}
+                  value={fieldValues[`${index}-rest`] ?? String(set.restDuration)}
-                  onChangeText={(val) => updateSet(index, { restDuration: Number(val) || 0 })}
+                  onChangeText={(val) => setFieldValues((prev) => ({ ...prev, [`${index}-rest`]: val }))}
+                  onBlur={() => {
+                    const num = Number(fieldValues[`${index}-rest`] ?? set.restDuration);
+                    updateSet(index, { restDuration: isNaN(num) || num < 0 ? 0 : num });
+                    setFieldValues((prev) => {
+                      const next = { ...prev };
+                      delete next[`${index}-rest`];
+                      return next;
+                    });
+                  }}
+                  placeholder="0"
+                  placeholderTextColor="#94a3b8"
                   className="bg-white border border-slate-300 rounded-lg px-3 py-2 text-slate-900"
                 />
               </View>