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.go

@@ -0,0 +1,67 @@
+package pipeline
+
+import (
+	"fmt"
+	"strings"
+
+	"evobgp/internal/birdfmt"
+	"evobgp/internal/store"
+)
+
+// BirdLocalsForSpeaker merges tenant settings with per-speaker meta_json overrides.
+func BirdLocalsForSpeaker(st store.Backend, tenantID, speakerID string) birdLocals {
+	loc := birdLocalsFromStore(st, tenantID)
+	if st == nil || strings.TrimSpace(speakerID) == "" {
+		return loc
+	}
+	sp, err := st.GetSpeaker(tenantID, speakerID)
+	if err != nil || sp == nil {
+		return loc
+	}
+	meta := store.ParseSpeakerMeta(sp.MetaJSON)
+	if s := strings.TrimSpace(meta.BirdBgpSourceIPv4); s != "" {
+		loc.routerID = s
+		loc.localV4 = s
+	}
+	if s := strings.TrimSpace(meta.BirdBgpSourceIPv6); s != "" {
+		loc.localV6 = s
+	}
+	return loc
+}
+
+// OverlayFragmentsForSpeaker re-renders bird.conf and peers fragment with speaker-specific BIRD locals.
+func OverlayFragmentsForSpeaker(st store.Backend, tenantID, speakerID, revisionID string, frags map[string]string) (map[string]string, error) {
+	if frags == nil {
+		return nil, fmt.Errorf("pipeline: overlay: nil fragments")
+	}
+	locals := BirdLocalsForSpeaker(st, tenantID, speakerID)
+	out := make(map[string]string, len(frags))
+	for k, v := range frags {
+		out[k] = v
+	}
+	moduleHint := "aggregate"
+	if main := frags["bird.conf"]; main != "" {
+		if idx := strings.Index(main, "trigger module "); idx >= 0 {
+			rest := main[idx+len("trigger module "):]
+			if end := strings.Index(rest, ")"); end > 0 {
+				moduleHint = strings.TrimSpace(rest[:end])
+			}
+		}
+	}
+	main, err := birdfmt.RenderMainBirdConf(birdfmt.MainBirdConfOptions{
+		RouterID: locals.routerID,
+		Includes: birdfmt.StandardIncludeFragments(),
+		Preamble: fmt.Sprintf("EvoBGP tenant aggregate config (trigger module %s) revision %s speaker %s", moduleHint, revisionID, speakerID),
+	})
+	if err != nil {
+		return nil, err
+	}
+	out["bird.conf"] = main
+	peersBody, err := renderPeersBirdFragment(st, tenantID, locals)
+	if err != nil {
+		return nil, err
+	}
+	pPeers := birdfmt.FragmentIncludePath(birdfmt.FragmentPeers)
+	out[pPeers] = peersBody
+	return out, nil
+}