♲ Refactor configuration to use viper with context propagation

- Replace global ConfigPath and Overrides with viper-based configuration
- Add viper.New() to create configurable viper instances
- Store viper and unmarshaled Config struct in context for testability
- Add RetrieveFromContext and AddToContext helper functions
- Update files.Append to accept context and retrieve config from it
- Update formatters.Preferred and formatters.New to accept context
- Add PersistentPreRunE in CLI to create and configure viper instance
- Support -c flag for custom config file path
- Support -v flag for config value overrides
- Update all test files to create viper and add to context
- Remove unused config types and load functions
- Add viper as dependency with automatic env var support (MYLOG_*)

files/append.go

@@ -1,6 +1,7 @@
 package files
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"os"
@@ -11,11 +12,8 @@ import (
 	"codeberg.org/danjones000/my-log/models"
 )
 
-func Append(l models.Log) error {
-	conf, err := config.Load()
-	if err != nil {
-		return err
-	}
+func Append(ctx context.Context, l models.Log) error {
+	_, conf := config.RetrieveFromContext(ctx)
 
 	filename := l.Name
 	if conf.Input.DotFolder {
@@ -27,7 +25,7 @@ func Append(l models.Log) error {
 	}
 	path := fp.Join(conf.Input.Path, filename)
 	dir := fp.Dir(path)
-	err = os.MkdirAll(dir, 0750)
+	err := os.MkdirAll(dir, 0750)
 	if err != nil {
 		return err
 	}