fix(parser): improve priority calculation accuracy using math.Round

Refactored PriorityAsRemind to use floating point division and rounding
for more precise priority mapping.

internal/parser/parser.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"math"
 	"regexp"
 	"strings"
 	"time"
@@ -104,12 +105,10 @@ func (t Task) PriorityAsRemind() int {
 	if p < 'A' || p > 'Z' {
 		return 5000
 	}
-	step := 9999 / 25 // 399
-	val := 9999 - int(p-'A')*step
-	if p == 'Z' {
-		return 0
-	}
-	return val
+	pInt := int(p) - 65 // 'A' = 65
+	value := 9999 - (float64(pInt) * (float64(9999) / float64(25)))
+	value = math.Round(value)
+	return int(value)
 }
 
 func (t Task) MarshalJSON() ([]byte, error) {