Added a dedupe processor, and moved processor packages under processors/*

processors/normalize/doc.go

@@ -0,0 +1,17 @@
+// Package normalize provides a concrete normalization processor for feedkit pipelines.
+//
+// Motivation:
+// Many daemons have sources that:
+//  1. fetch raw upstream data (often JSON), and
+//  2. transform it into a domain's normalized payload format.
+//
+// Doing both steps inside Source.Poll works, but tends to make sources large and
+// encourages duplication (unit conversions, common mapping helpers, etc.).
+//
+// This package lets a source emit a "raw" event (e.g., Schema="raw.openweather.current.v1",
+// Payload=json.RawMessage), and then a normalize.Processor can convert it into a
+// normalized event (e.g., Schema="weather.observation.v1", Payload=WeatherObservation{}).
+//
+// Key property: normalization is optional.
+// If no Normalizer matches an event, Processor passes it through unchanged by default.
+package normalize