Replace custom stringsTrim with strings.TrimSpace

Remove duplicate stringsTrim implementations in stats and tmux packages,
replacing all call sites with the standard library strings.TrimSpace.

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

2 files changed, 8 insertions, 22 deletions

diff --git a/internal/stats/stats.go b/internal/stats/stats.go
index 4b05617..939e1aa 100644
--- a/internal/stats/stats.go
+++ b/internal/stats/stats.go
@@ -13,6 +13,7 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
+	"strings"
 	"sync/atomic"
 	"time"
 )
@@ -264,7 +265,7 @@ func TakeSnapshot() (Snapshot, error) {
 
 // CacheDir resolves the cache directory for stats.
 func CacheDir() (string, error) {
-	if x := os.Getenv("XDG_CACHE_HOME"); stringsTrim(x) != "" {
+	if x := os.Getenv("XDG_CACHE_HOME"); strings.TrimSpace(x) != "" {
 		return filepath.Join(x, "hexai"), nil
 	}
 	home, err := os.UserHomeDir()
@@ -274,22 +275,6 @@ func CacheDir() (string, error) {
 	return filepath.Join(home, ".local", "hexai", "cache"), nil
 }
 
-// stringsTrim is a tiny helper to avoid importing strings everywhere here.
-func stringsTrim(s string) string {
-	i := 0
-	j := len(s)
-	for i < j && (s[i] == ' ' || s[i] == '\t' || s[i] == '\n' || s[i] == '\r') {
-		i++
-	}
-	for j > i && (s[j-1] == ' ' || s[j-1] == '\t' || s[j-1] == '\n' || s[j-1] == '\r') {
-		j--
-	}
-	if i == 0 && j == len(s) {
-		return s
-	}
-	return s[i:j]
-}
-
 // DebugString returns a compact single-line view of a snapshot (useful for logs).
 func (s Snapshot) DebugString() string {
 	return "Σ reqs=" + strconv.FormatInt(s.Global.Reqs, 10) + " rpm=" + fmt.Sprintf("%.2f", s.RPM)
diff --git a/internal/stats/stats_test.go b/internal/stats/stats_test.go
index 75c1c5b..45f9e2a 100644
--- a/internal/stats/stats_test.go
+++ b/internal/stats/stats_test.go
@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"os"
 	"path/filepath"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -102,7 +103,7 @@ func TestCacheDir_FallbackHome(t *testing.T) {
 }
 
 // TestCacheDir_WhitespaceXDG covers the branch where XDG_CACHE_HOME contains
-// only whitespace, which stringsTrim reduces to "" so the fallback is used.
+// only whitespace, which strings.TrimSpace reduces to "" so the fallback is used.
 func TestCacheDir_WhitespaceXDG(t *testing.T) {
 	t.Setenv("XDG_CACHE_HOME", "  \t\n ")
 	got, err := CacheDir()
@@ -140,7 +141,7 @@ func TestSetWindow_ClampHigh(t *testing.T) {
 // has no leading or trailing whitespace, so the original string is returned.
 func TestStringsTrim_NoTrimNeeded(t *testing.T) {
 	in := "hello"
-	got := stringsTrim(in)
+	got := strings.TrimSpace(in)
 	if got != "hello" {
 		t.Fatalf("expected %q, got %q", "hello", got)
 	}
@@ -148,7 +149,7 @@ func TestStringsTrim_NoTrimNeeded(t *testing.T) {
 
 // TestStringsTrim_AllWhitespace covers trimming a string that is entirely whitespace.
 func TestStringsTrim_AllWhitespace(t *testing.T) {
-	got := stringsTrim("  \t\r\n  ")
+	got := strings.TrimSpace("  \t\r\n  ")
 	if got != "" {
 		t.Fatalf("expected empty, got %q", got)
 	}
@@ -156,7 +157,7 @@ func TestStringsTrim_AllWhitespace(t *testing.T) {
 
 // TestStringsTrim_LeadingAndTrailing covers trimming from both ends.
 func TestStringsTrim_LeadingAndTrailing(t *testing.T) {
-	got := stringsTrim("  abc  ")
+	got := strings.TrimSpace("  abc  ")
 	if got != "abc" {
 		t.Fatalf("expected %q, got %q", "abc", got)
 	}
@@ -164,7 +165,7 @@ func TestStringsTrim_LeadingAndTrailing(t *testing.T) {
 
 // TestStringsTrim_Empty covers the empty string edge case.
 func TestStringsTrim_Empty(t *testing.T) {
-	got := stringsTrim("")
+	got := strings.TrimSpace("")
 	if got != "" {
 		t.Fatalf("expected empty, got %q", got)
 	}