dispatch: allow empty route kinds (match all) + add routing tests

- config: permit routes[].kinds to be omitted/empty; treat as "all kinds"
- dispatch: compile empty kinds to Route{Kinds:nil} (match all kinds)
- tests: add coverage for route compilation + config validation edge cases

Files:
- config/load.go
- config/config.go
- dispatch/routes.go
- config/validate_test.go
- dispatch/routes_test.go

config/config.go

@@ -54,7 +54,10 @@ type RouteConfig struct {
 	Sink string `yaml:"sink"` // sink name
 
 	// Kinds is domain-defined. feedkit only enforces that each entry is non-empty.
-	// Whether a given daemon "recognizes" a kind is domain-specific validation.
+	//
+	// If Kinds is omitted or empty, the route matches ALL kinds.
+	// This is useful when you want explicit per-sink routing rules even when a
+	// particular sink should receive everything.
 	Kinds []string `yaml:"kinds"`
 }
 

config/load.go

@@ -133,16 +133,12 @@ func (c *Config) Validate() error {
 			m.Add(fieldErr(path+".sink", fmt.Sprintf("references unknown sink %q (define it under sinks:)", r.Sink)))
 		}
 
-		if len(r.Kinds) == 0 {
-			// You could relax this later (e.g. empty == "all kinds"), but for now
-			// keeping it strict prevents accidental "route does nothing".
-			m.Add(fieldErr(path+".kinds", "must contain at least one kind"))
-		} else {
-			for j, k := range r.Kinds {
-				kpath := fmt.Sprintf("%s.kinds[%d]", path, j)
-				if strings.TrimSpace(k) == "" {
-					m.Add(fieldErr(kpath, "kind cannot be empty"))
-				}
+		// Kinds is optional. If omitted or empty, the route matches ALL kinds.
+		// If provided, each entry must be non-empty.
+		for j, k := range r.Kinds {
+			kpath := fmt.Sprintf("%s.kinds[%d]", path, j)
+			if strings.TrimSpace(k) == "" {
+				m.Add(fieldErr(kpath, "kind cannot be empty"))
 			}
 		}
 	}

config/validate_test.go

@@ -0,0 +1,48 @@
+package config
+
+import (
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestValidate_RouteKindsEmptyIsAllowed(t *testing.T) {
+	cfg := &Config{
+		Sources: []SourceConfig{
+			{Name: "src1", Driver: "driver1", Every: Duration{Duration: time.Minute}},
+		},
+		Sinks: []SinkConfig{
+			{Name: "sink1", Driver: "stdout"},
+		},
+		Routes: []RouteConfig{
+			{Sink: "sink1", Kinds: nil},        // omitted
+			{Sink: "sink1", Kinds: []string{}}, // explicit empty
+		},
+	}
+
+	if err := cfg.Validate(); err != nil {
+		t.Fatalf("expected no error, got: %v", err)
+	}
+}
+
+func TestValidate_RouteKindsRejectsBlankEntries(t *testing.T) {
+	cfg := &Config{
+		Sources: []SourceConfig{
+			{Name: "src1", Driver: "driver1", Every: Duration{Duration: time.Minute}},
+		},
+		Sinks: []SinkConfig{
+			{Name: "sink1", Driver: "stdout"},
+		},
+		Routes: []RouteConfig{
+			{Sink: "sink1", Kinds: []string{"observation", "   ", "alert"}},
+		},
+	}
+
+	err := cfg.Validate()
+	if err == nil {
+		t.Fatalf("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "routes[0].kinds[1]") {
+		t.Fatalf("expected error to mention blank kind entry, got: %v", err)
+	}
+}