Update Go version to 1.26 (#31)

- Update go.mod to Go 1.26
- Update GitHub Actions workflows to Go 1.26
- Fix fmt.Sprintf format string checks (Go 1.26 stricter validation)
- All tests passing

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: aurc

.github/workflows/feature.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v2
       with:
-        go-version: 1.23
+        go-version: 1.26
 
     - name: Build
       run: go build -v ./...

.github/workflows/go.yml

@@ -13,7 +13,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v2
       with:
-        go-version: 1.23
+        go-version: 1.26
 
 #    - name: Install dependencies
 #      run: |

go.mod

@@ -1,6 +1,6 @@
 module github.com/aurc/loggo
 
-go 1.23
+go 1.26
 
 require (
 	cloud.google.com/go/logging v1.11.0

internal/loggo/splash_screen.go

@@ -156,17 +156,17 @@ func (t *SplashScreen) PrintCanvasAsColorString(foreground, shade rune, foregrou
 			switch t.canvas[row][col] {
 			case foreground:
 				if prev != fg {
-					sb.WriteString(fmt.Sprintf(foregroundColor))
+					sb.WriteString(foregroundColor)
 					prev = fg
 				}
 			case shade:
 				if prev != sh {
-					sb.WriteString(fmt.Sprintf(shadeColor))
+					sb.WriteString(shadeColor)
 					prev = sh
 				}
 			default:
 				if prev != bg {
-					sb.WriteString(fmt.Sprintf(backgroundColor))
+					sb.WriteString(backgroundColor)
 					prev = bg
 				}
 			}