feat(prompts): add prompts loader and configuration management

- Implemented a new prompts loader in `loader.go` to manage prompt templates and configurations.
- Introduced caching mechanism for prompt configurations to optimize loading.
- Added functions to apply platform-specific prompt template overrides.
- Created unit tests in `loader_test.go` to validate prompt configuration loading and reloading behavior.
- Ensured that the last valid configuration is retained in case of errors during reload.

server/cmd/dev-seed/main.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -94,6 +95,7 @@ func main() {
 	if err != nil {
 		log.Fatalf("load config: %v", err)
 	}
+	prompts.SetConfigFile(filepath.Join(filepath.Dir(configPath), "prompts.yml"))
 
 	ctx := context.Background()
 	businessPool, err := pgxpool.New(ctx, cfg.Database.DSN())