refactor: rename ContentRouter to DelegatedRouter

- introduce DelegatedRouter interface for delegated routing operations
- keep ContentRouter as deprecated alias for backward compatibility
- update internal server struct to use DelegatedRouter
- clarify interface focuses on querying with IPNS publishing support
- note that additional publishing methods may be added via IPIP process

this better aligns with the Delegated Routing V1 HTTP API spec
and clarifies that this interface handles all routing operations
(content, peers, values, DHT), not just content routing

Author: lidel

routing/http/contentrouter/contentrouter.go

@@ -23,7 +23,7 @@ var logger = logging.Logger("routing/http/contentrouter")
 
 const ttl = 24 * time.Hour
 
-// A Client provides HTTP Content Routing methods. See also [server.ContentRouter].
+// A Client provides HTTP Delegated Routing methods. See also [server.DelegatedRouter].
 type Client interface {
 	FindProviders(ctx context.Context, key cid.Cid) (iter.ResultIter[types.Record], error)
 	ProvideBitswap(ctx context.Context, keys []cid.Cid, ttl time.Duration) (time.Duration, error)

routing/http/server/server.go

@@ -62,7 +62,14 @@ type FindProvidersAsyncResponse struct {
 	Error            error
 }
 
-type ContentRouter interface {
+// DelegatedRouter provides the Delegated Routing V1 HTTP API for offloading
+// routing operations to another process/server.
+//
+// This interface focuses on querying operations for content providers, peers,
+// IPNS records, and DHT routing information. It also supports delegated IPNS
+// publishing. Additional publishing methods may be added in the future via the
+// IPIP process as the ecosystem evolves and new needs arise.
+type DelegatedRouter interface {
 	// FindProviders searches for peers who are able to provide the given [cid.Cid].
 	// Limit indicates the maximum amount of results to return; 0 means unbounded.
 	FindProviders(ctx context.Context, cid cid.Cid, limit int) (iter.ResultIter[types.Record], error)
@@ -94,6 +101,10 @@ type ContentRouter interface {
 	GetClosestPeers(ctx context.Context, peerID, closerThan peer.ID, count int) (iter.ResultIter[*types.PeerRecord], error)
 }
 
+// ContentRouter is deprecated, use DelegatedRouter instead.
+// Deprecated: use DelegatedRouter. ContentRouter will be removed in a future version.
+type ContentRouter = DelegatedRouter
+
 // Deprecated: protocol-agnostic provide is being worked on in [IPIP-378]:
 //
 // [IPIP-378]: https://github.com/ipfs/specs/pull/378
@@ -205,7 +216,7 @@ func Handler(svc ContentRouter, opts ...Option) http.Handler {
 var handlerCount atomic.Int32
 
 type server struct {
-	svc                   ContentRouter
+	svc                   DelegatedRouter
 	disableNDJSON         bool
 	recordsLimit          int
 	streamingRecordsLimit int