style: run gofmt -s across all Go files

Fixes Go Report Card gofmt score from 52% to 100%.
Pure formatting changes — no logic modifications.

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

internal/api/handler/job_handler_test.go

@@ -12,8 +12,8 @@ import (
 
 // MockJobService is a mock implementation of JobService interface.
 type MockJobService struct {
-	ListJobsFn func(status, jobType string, page, perPage int) ([]domain.Job, int64, error)
-	GetJobFn   func(id string) (*domain.Job, error)
+	ListJobsFn  func(status, jobType string, page, perPage int) ([]domain.Job, int64, error)
+	GetJobFn    func(id string) (*domain.Job, error)
 	CancelJobFn func(id string) error
 }
 

internal/api/handler/validation.go

@@ -126,7 +126,7 @@ func isValidHostnameChar(r rune) bool {
 		r == '.' ||
 		r == '-' ||
 		r == '_' || // Underscores are sometimes allowed
-		r == '*'    // Wildcard support
+		r == '*' // Wildcard support
 }
 
 // Error method makes ValidationError satisfy the error interface.