feedkit: split the former maximumdirect.net/weatherd project in two.

feedkit now contains a reusable core, while weatherfeeder is a concrete implementation that includes weather-specific functions.

sources/source.go

@@ -0,0 +1,30 @@
+package sources
+
+import (
+	"context"
+
+	"gitea.maximumdirect.net/ejr/feedkit/event"
+)
+
+// Source is a configured polling job that emits 0..N events per poll.
+//
+// Source implementations live in domain modules (weatherfeeder/newsfeeder/...)
+// and are registered into a feedkit sources.Registry.
+//
+// feedkit infrastructure treats Source as opaque; it just calls Poll()
+// on the configured cadence and publishes the resulting events.
+type Source interface {
+	// Name is the configured source name (used for logs and included in emitted events).
+	Name() string
+
+	// Kind is the "primary kind" emitted by this source.
+	//
+	// This is mainly useful as a *safety check* (e.g. config says kind=forecast but
+	// driver emits observation). Some future sources may emit multiple kinds; if/when
+	// that happens, we can evolve this interface (e.g., make Kind optional, or remove it).
+	Kind() event.Kind
+
+	// Poll fetches from upstream and returns 0..N events.
+	// Implementations should honor ctx.Done() for network calls and other I/O.
+	Poll(ctx context.Context) ([]event.Event, error)
+}