[agent-network] Management: store, manager, synthesizer, policy engine, provider catalog, HTTP/gRPC API

Adds the account-scoped agent-network module: provider/policy/budget CRUD and
store, the reverse-proxy service synthesizer, policy selection + limit
enforcement, the provider catalog (incl. Vertex AI and AWS Bedrock entries),
and the management HTTP + proxy gRPC surfaces.

management/internals/modules/peers/manager.go

@@ -220,12 +220,36 @@ func (m *managerImpl) GetPeerID(ctx context.Context, peerKey string) (string, er
 func (m *managerImpl) CreateProxyPeer(ctx context.Context, accountID string, peerKey string, cluster string) error {
 	existingPeerID, err := m.store.GetPeerIDByKey(ctx, store.LockingStrengthNone, peerKey)
 	if err == nil && existingPeerID != "" {
-		// Peer already exists
+		// Same pubkey already registered — idempotent.
 		return nil
 	}
 
+	// Dedupe stale embedded peer records for the same (account, cluster).
+	// The proxy generates a fresh WireGuard keypair on every startup
+	// (proxy/internal/roundtrip/netbird.go), so without this sweep the
+	// prior embedded peer would linger forever — holding its CGNAT IP
+	// allocation, polluting other peers' rosters, and (most visibly)
+	// leaving the synth DNS pointing at the dead address. The
+	// (account, cluster) tuple identifies "the embedded peer for this
+	// proxy instance at this cluster"; any record matching that tuple
+	// with a different pubkey is by definition stale and must go.
+	staleIDs, err := m.findStaleEmbeddedProxyPeers(ctx, accountID, cluster, peerKey)
+	if err != nil {
+		return fmt.Errorf("scan for stale embedded proxy peers: %w", err)
+	}
+	if len(staleIDs) > 0 {
+		// userID="" + checkConnected=false: the deletion is initiated
+		// by management itself on behalf of the freshly-registering
+		// proxy, not by an end user; the stale peer may still be
+		// marked Connected from its prior session, but its session is
+		// dead by definition (its key no longer exists).
+		if err := m.DeletePeers(ctx, accountID, staleIDs, "", false); err != nil {
+			return fmt.Errorf("delete stale embedded proxy peers %v: %w", staleIDs, err)
+		}
+	}
+
 	name := fmt.Sprintf("proxy-%s", xid.New().String())
-	peer := &peer.Peer{
+	newPeer := &peer.Peer{
 		Ephemeral: true,
 		ProxyMeta: peer.ProxyMeta{
 			Cluster:  cluster,
@@ -242,10 +266,36 @@ func (m *managerImpl) CreateProxyPeer(ctx context.Context, accountID string, pee
 		},
 	}
 
-	_, _, _, _, err = m.accountManager.AddPeer(ctx, accountID, "", "", peer, true)
+	_, _, _, _, err = m.accountManager.AddPeer(ctx, accountID, "", "", newPeer, true)
 	if err != nil {
 		return fmt.Errorf("failed to create proxy peer: %w", err)
 	}
 
 	return nil
 }
+
+// findStaleEmbeddedProxyPeers returns the peer IDs of embedded proxy peer
+// records in accountID that target the same cluster but carry a different
+// WireGuard pubkey than the freshly-registering one. Used by CreateProxyPeer
+// to garbage-collect stale records left behind when the proxy restarts with a
+// regenerated keypair.
+func (m *managerImpl) findStaleEmbeddedProxyPeers(ctx context.Context, accountID, cluster, newKey string) ([]string, error) {
+	account, err := m.store.GetAccount(ctx, accountID)
+	if err != nil {
+		return nil, err
+	}
+	var stale []string
+	for _, p := range account.Peers {
+		if p == nil || !p.ProxyMeta.Embedded {
+			continue
+		}
+		if p.ProxyMeta.Cluster != cluster {
+			continue
+		}
+		if p.Key == newKey {
+			continue
+		}
+		stale = append(stale, p.ID)
+	}
+	return stale, nil
+}