feat(15-01): add Discord, Slack, DevTo recon sources and wire all six

- DiscordSource uses dorking approach against configurable search endpoint
- SlackSource uses dorking against slack-archive indexers
- DevToSource searches dev.to API articles list + detail for body_markdown
- RegisterAll extended to include all 6 Phase 15 forum sources
- All credentialless, use ciLogKeyPattern for key detection

pkg/recon/sources/devto_test.go

@@ -0,0 +1,86 @@
+package sources
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/salvacybersec/keyhunter/pkg/providers"
+	"github.com/salvacybersec/keyhunter/pkg/recon"
+)
+
+func TestDevTo_Name(t *testing.T) {
+	s := &DevToSource{}
+	if s.Name() != "devto" {
+		t.Fatalf("expected devto, got %s", s.Name())
+	}
+}
+
+func TestDevTo_Enabled(t *testing.T) {
+	s := &DevToSource{}
+	if !s.Enabled(recon.Config{}) {
+		t.Fatal("DevToSource should always be enabled (credentialless)")
+	}
+}
+
+func TestDevTo_Sweep(t *testing.T) {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/api/articles", func(w http.ResponseWriter, r *http.Request) {
+		// Check if this is a detail request (/api/articles/42).
+		if r.URL.Path == "/api/articles/42" {
+			w.Header().Set("Content-Type", "application/json")
+			_, _ = w.Write([]byte(`{
+				"body_markdown":"# Tutorial\nSet your api_key = \"sk-proj-ABCDEF1234567890abcdef\" in .env\n",
+				"url":"https://dev.to/user/tutorial-post"
+			}`))
+			return
+		}
+		// List endpoint.
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`[{"id":42,"url":"https://dev.to/user/tutorial-post"}]`))
+	})
+	// Also handle the detail path with the ID suffix.
+	mux.HandleFunc("/api/articles/42", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{
+			"body_markdown":"# Tutorial\nSet your api_key = \"sk-proj-ABCDEF1234567890abcdef\" in .env\n",
+			"url":"https://dev.to/user/tutorial-post"
+		}`))
+	})
+
+	srv := httptest.NewServer(mux)
+	defer srv.Close()
+
+	reg := providers.NewRegistryFromProviders([]providers.Provider{
+		{Name: "openai", Keywords: []string{"sk-proj-"}},
+	})
+
+	s := &DevToSource{
+		BaseURL:  srv.URL,
+		Registry: reg,
+		Client:   NewClient(),
+	}
+
+	out := make(chan recon.Finding, 10)
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	err := s.Sweep(ctx, "", out)
+	close(out)
+	if err != nil {
+		t.Fatalf("Sweep error: %v", err)
+	}
+
+	var findings []recon.Finding
+	for f := range out {
+		findings = append(findings, f)
+	}
+	if len(findings) == 0 {
+		t.Fatal("expected at least one finding from dev.to article")
+	}
+	if findings[0].SourceType != "recon:devto" {
+		t.Fatalf("expected recon:devto, got %s", findings[0].SourceType)
+	}
+}