perf: hoist per-call allocations to package-level variables

- Move audioExtensions/audioTypes slices to package var in media.go
- Use strconv.Itoa instead of fmt.Sprintf for int conversion
- Replace inline regexp.MustCompile with existing reTaskLine var

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkg/agent/memory.go

@@ -562,9 +562,8 @@ func (ms *MemoryStore) GetPlanContext() string {
 	currentPhase := ms.GetCurrentPhase()
 	totalPhases := ms.GetTotalPhases()
 
-	// Extract task description
 	taskLine := ""
-	if m := regexp.MustCompile(`(?m)^> Task:\s*(.+)`).FindStringSubmatch(content); len(m) >= 2 {
+	if m := reTaskLine.FindStringSubmatch(content); len(m) >= 2 {
 		taskLine = strings.TrimSpace(m[1])
 	}
 
@@ -660,7 +659,7 @@ func (ms *MemoryStore) FormatPlanDisplay() string {
 	}
 
 	taskLine := ""
-	if m := regexp.MustCompile(`(?m)^> Task:\s*(.+)`).FindStringSubmatch(content); len(m) >= 2 {
+	if m := reTaskLine.FindStringSubmatch(content); len(m) >= 2 {
 		taskLine = strings.TrimSpace(m[1])
 	}
 	status := ms.GetPlanStatus()

pkg/skills/clawhub_registry.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"strconv"
 	"time"
 
 	"github.com/sipeed/picoclaw/pkg/utils"
@@ -111,7 +112,7 @@ func (c *ClawHubRegistry) Search(ctx context.Context, query string, limit int) (
 	q := u.Query()
 	q.Set("q", query)
 	if limit > 0 {
-		q.Set("limit", fmt.Sprintf("%d", limit))
+		q.Set("limit", strconv.Itoa(limit))
 	}
 	u.RawQuery = q.Encode()
 

pkg/utils/media.go

@@ -13,10 +13,13 @@ import (
 	"github.com/sipeed/picoclaw/pkg/logger"
 )
 
+var (
+	audioExtensions = []string{".mp3", ".wav", ".ogg", ".m4a", ".flac", ".aac", ".wma"}
+	audioTypes      = []string{"audio/", "application/ogg", "application/x-ogg"}
+)
+
 // IsAudioFile checks if a file is an audio file based on its filename extension and content type.
 func IsAudioFile(filename, contentType string) bool {
-	audioExtensions := []string{".mp3", ".wav", ".ogg", ".m4a", ".flac", ".aac", ".wma"}
-	audioTypes := []string{"audio/", "application/ogg", "application/x-ogg"}
 
 	for _, ext := range audioExtensions {
 		if strings.HasSuffix(strings.ToLower(filename), ext) {