Cleaned up documentation and removed stubs and TODOs throughout the application

sinks/helpers.go

@@ -7,6 +7,25 @@ import (
 	"gitea.maximumdirect.net/ejr/feedkit/config"
 )
 
+// requireStringParam returns a non-empty string sink param.
+//
+// This helper is intentionally local to sinks rather than config so
+// driver-specific validation stays close to the adapters that use it.
+func requireStringParam(cfg config.SinkConfig, key string) (string, error) {
+	v, ok := cfg.Params[key]
+	if !ok {
+		return "", fmt.Errorf("sink %q: params.%s is required", cfg.Name, key)
+	}
+	s, ok := v.(string)
+	if !ok {
+		return "", fmt.Errorf("sink %q: params.%s must be a string", cfg.Name, key)
+	}
+	if strings.TrimSpace(s) == "" {
+		return "", fmt.Errorf("sink %q: params.%s cannot be empty", cfg.Name, key)
+	}
+	return s, nil
+}
+
 // RegisterPostgresSchemaForConfiguredSinks registers one Postgres schema for each
 // configured sink using driver=postgres.
 func RegisterPostgresSchemaForConfiguredSinks(cfg *config.Config, schema PostgresSchema) error {