feat(reverse-proxy): clusters API surfaces type, online status, and capability flags (#6148)

The cluster listing now answers three questions in one round-trip
instead of forcing the dashboard to cross-reference the domains API:
which clusters can this account see, are they currently up, and what
do they support. The ProxyCluster wire type drops the boolean
self_hosted in favour of a `type` enum (`account` / `shared`) plus
explicit `online`, `supports_custom_ports`, `require_subdomain`, and
`supports_crowdsec` fields.

Store query reworked so offline clusters still appear (no last_seen
WHERE), with online and connected_proxies both derived from the
existing 2-min active window via portable CASE expressions; the
1-hour heartbeat reaper still removes long-stale rows. Service
manager enriches each cluster with the capability flags via the
existing per-cluster lookups (CapabilityProvider now also exposes
ClusterSupportsCrowdSec).

GetActiveClusterAddresses* keep their tight 2-min filter so service
routing and domain enumeration aren't pulled into the wider window.

The hard cut removes self_hosted from the response — the dashboard is
the only consumer and is updated in the matching PR; no transitional
field is shipped.

Adds a cross-engine regression test asserting offline clusters
surface, connected_proxies counts only fresh proxies, and
account-scoped BYOP clusters never leak across accounts.

management/server/store/sql_store.go

@@ -5736,19 +5736,67 @@ func (s *SqlStore) DeleteAccountCluster(ctx context.Context, clusterAddress, acc
 	return nil
 }
 
-func (s *SqlStore) GetActiveProxyClusters(ctx context.Context, accountID string) ([]proxy.Cluster, error) {
-	var clusters []proxy.Cluster
+// GetProxyClusters returns every cluster the account can see (shared
+// plus its own BYOP), regardless of whether any proxy in the cluster
+// is currently heartbeating. Online and ConnectedProxies are derived
+// from the 2-min active window so the dashboard can render offline
+// clusters distinctly; the 1-hour heartbeat reaper still removes rows
+// that go quiet for too long.
+//
+// AccountOwned is determined by whether any proxy row in the group
+// carries a non-NULL account_id; the caller maps that to Cluster.Type.
+// Capability flags are NOT filled here — the handler enriches them via
+// the per-cluster capability lookups.
+func (s *SqlStore) GetProxyClusters(ctx context.Context, accountID string) ([]proxy.Cluster, error) {
+	activeCutoff := time.Now().Add(-proxyActiveThreshold)
 
+	type clusterRow struct {
+		ID               string
+		Address          string
+		ConnectedProxies int
+		Online           bool
+		AccountOwned     bool
+	}
+
+	var rows []clusterRow
 	result := s.db.Model(&proxy.Proxy{}).
-		Select("MIN(id) as id, cluster_address as address, COUNT(*) as connected_proxies, COUNT(account_id) > 0 as self_hosted").
-		Where("status = ? AND last_seen > ? AND (account_id IS NULL OR account_id = ?)",
-			proxy.StatusConnected, time.Now().Add(-proxyActiveThreshold), accountID).
+		Select(
+			"MIN(id) AS id, "+
+				"cluster_address AS address, "+
+				// COUNT(CASE WHEN ... THEN 1 END) counts only non-NULL — i.e. only
+				// rows that satisfy the predicate — so it works portably across
+				// sqlite/postgres/mysql without dialect-specific FILTER syntax.
+				"COUNT(CASE WHEN status = ? AND last_seen > ? THEN 1 END) AS connected_proxies, "+
+				// MAX(CASE …) > 0 expresses BOOL_OR in a way Postgres tolerates
+				// (Postgres can't MAX a boolean column).
+				"MAX(CASE WHEN status = ? AND last_seen > ? THEN 1 ELSE 0 END) > 0 AS online, "+
+				"MAX(CASE WHEN account_id IS NOT NULL THEN 1 ELSE 0 END) > 0 AS account_owned",
+			proxy.StatusConnected, activeCutoff,
+			proxy.StatusConnected, activeCutoff,
+		).
+		Where("account_id IS NULL OR account_id = ?", accountID).
 		Group("cluster_address").
-		Scan(&clusters)
+		Scan(&rows)
 
 	if result.Error != nil {
-		log.WithContext(ctx).Errorf("failed to get active proxy clusters: %v", result.Error)
-		return nil, status.Errorf(status.Internal, "get active proxy clusters")
+		log.WithContext(ctx).Errorf("failed to get proxy clusters: %v", result.Error)
+		return nil, status.Errorf(status.Internal, "get proxy clusters")
+	}
+
+	clusters := make([]proxy.Cluster, 0, len(rows))
+	for _, r := range rows {
+		c := proxy.Cluster{
+			ID:               r.ID,
+			Address:          r.Address,
+			Online:           r.Online,
+			ConnectedProxies: r.ConnectedProxies,
+		}
+		if r.AccountOwned {
+			c.Type = proxy.ClusterTypeAccount
+		} else {
+			c.Type = proxy.ClusterTypeShared
+		}
+		clusters = append(clusters, c)
 	}
 
 	return clusters, nil