feat(remote-speakers): enhance remote speaker management and API integration

- Added support for remote speaker configuration in the README and documentation.
- Implemented a new endpoint for retrieving the bundle signing public key.
- Updated the `evobgp-agent` to include a `serve` command for Panel→Node sync API.
- Enhanced CI workflow to validate remote speaker compose files.
- Introduced new fields in the API and UI for managing speaker metadata, including dispatch status and sync status.
- Improved error handling and response formatting in speaker-related API endpoints.
- Updated documentation to reflect changes in remote speaker functionality and usage guidelines.

internal/pipeline/speaker_overlay_test.go

@@ -0,0 +1,42 @@
+package pipeline_test
+
+import (
+	"strings"
+	"testing"
+
+	"evobgp/internal/pipeline"
+	"evobgp/internal/store"
+)
+
+func TestOverlayFragmentsForSpeaker_differentRouterID(t *testing.T) {
+	m := store.NewMemory()
+	m.SeedDemo()
+	tenant, _, _, _, _ := m.DemoIDs()
+	sp1, _ := m.CreateSpeaker(tenant, &store.Speaker{
+		Role:     "replica",
+		Endpoint: "https://203.0.113.1",
+		MetaJSON: `{"bird_bgp_source_ipv4":"203.0.113.1"}`,
+	})
+	sp2, _ := m.CreateSpeaker(tenant, &store.Speaker{
+		Role:     "replica",
+		Endpoint: "https://203.0.113.2",
+		MetaJSON: `{"bird_bgp_source_ipv4":"203.0.113.2"}`,
+	})
+	base := map[string]string{
+		"bird.conf": "router id 192.0.2.1;\n# EvoBGP tenant aggregate config (trigger module mod) revision rev1",
+	}
+	out1, err := pipeline.OverlayFragmentsForSpeaker(m, tenant, sp1.ID, "rev1", base)
+	if err != nil {
+		t.Fatal(err)
+	}
+	out2, err := pipeline.OverlayFragmentsForSpeaker(m, tenant, sp2.ID, "rev1", base)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(out1["bird.conf"], "203.0.113.1") {
+		t.Fatalf("sp1 router: %s", out1["bird.conf"])
+	}
+	if !strings.Contains(out2["bird.conf"], "203.0.113.2") {
+		t.Fatalf("sp2 router: %s", out2["bird.conf"])
+	}
+}