refactor: remove JobTemplate production code

Remove all JobTemplate model, store, handler, migrations, and wiring. Replaced by Application Definition system.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

internal/store/mysql.go

@@ -40,5 +40,5 @@ func NewGormDB(dsn string, zapLogger *zap.Logger, gormLevel string) (*gorm.DB, e
 
 // AutoMigrate runs GORM auto-migration for all models.
 func AutoMigrate(db *gorm.DB) error {
-	return db.AutoMigrate(&model.JobTemplate{})
+	return db.AutoMigrate(&model.Application{})
 }