normalizers: added a structure for normalizers; refactoring sources -> sources+normalizers is still todo.

internal/normalizers/builtins.go

@@ -0,0 +1,37 @@
+// FILE: ./internal/normalizers/builtins.go
+package normalizers
+
+import (
+	fknormalize "gitea.maximumdirect.net/ejr/feedkit/normalize"
+
+	"gitea.maximumdirect.net/ejr/weatherfeeder/internal/normalizers/nws"
+	"gitea.maximumdirect.net/ejr/weatherfeeder/internal/normalizers/openmeteo"
+	"gitea.maximumdirect.net/ejr/weatherfeeder/internal/normalizers/openweather"
+)
+
+// RegisterBuiltins registers all normalizers shipped with this binary.
+//
+// This mirrors internal/sources.RegisterBuiltins, but note the selection model:
+//
+//   - sources are built by name (cfg.Driver -> factory)
+//   - normalizers are selected by Match() (event.Schema -> first match wins)
+//
+// Registration order matters because feedkit normalize.Registry is “first match wins”.
+// In weatherfeeder we avoid ambiguity by matching strictly on schema constants, but
+// we still keep ordering stable as a best practice.
+//
+// If reg is nil, this function is a no-op.
+func RegisterBuiltins(reg *fknormalize.Registry) {
+	if reg == nil {
+		return
+	}
+
+	// Keep this intentionally boring: delegate registration to provider subpackages
+	// so main.go stays clean and each provider owns its own mapping logic.
+	//
+	// Order here should be stable across releases to reduce surprises when adding
+	// new normalizers.
+	nws.Register(reg)
+	openmeteo.Register(reg)
+	openweather.Register(reg)
+}