Rename span 'docloader.fetch' to 'activitypub.fetch_document' for consistency

This change aligns the document loader span name with the existing
naming convention used by other spans in the codebase, where all
ActivityPub-related operations use the 'activitypub.*' namespace.

Author: dahlia

CHANGES.md

@@ -30,7 +30,7 @@ To be released.
  -  Added OpenTelemetry spans for previously uninstrumented operations:
     [[#323]]
 
-     -  Added `docloader.fetch` span for document loader operations,
+     -  Added `activitypub.fetch_document` span for document loader operations,
         tracking URL fetching, HTTP redirects, and final document URLs.
      -  Added `activitypub.verify_key_ownership` span for cryptographic
         key ownership verification, recording actor ID, key ID, verification

docs/manual/opentelemetry.md

@@ -174,9 +174,9 @@ spans:
 | `activitypub.outbox`                                | Consumer    | Dequeues the ActivityPub activity to send.    |
 | `activitypub.outbox`                                | Producer    | Enqueues the ActivityPub activity to send.    |
 | `activitypub.parse_object`                          | Internal    | Parses the Activity Streams object.           |
+| `activitypub.fetch_document`                        | Client      | Fetches a remote JSON-LD document.            |
 | `activitypub.send_activity`                         | Client      | Sends the ActivityPub activity.               |
 | `activitypub.verify_key_ownership`                  | Internal    | Verifies actor ownership of a key.            |
-| `docloader.fetch`                                   | Client      | Fetches a remote JSON-LD document.            |
 | `http_signatures.sign`                              | Internal    | Signs the HTTP request.                       |
 | `http_signatures.verify`                            | Internal    | Verifies the HTTP request signature.          |
 | `ld_signatures.sign`                                | Internal    | Makes the Linked Data signature.              |

packages/fedify/src/runtime/docloader.test.ts

@@ -742,7 +742,7 @@ test("getDocumentLoader() records OpenTelemetry span", async (t) => {
       assertEquals(result.documentUrl, "https://example.com/doc");
 
       // Check that the span was recorded
-      const spans = exporter.getSpans("docloader.fetch");
+      const spans = exporter.getSpans("activitypub.fetch_document");
       assertEquals(spans.length, 1);
       const span = spans[0];
 
@@ -785,7 +785,7 @@ test("getDocumentLoader() records OpenTelemetry span", async (t) => {
       assertEquals(result.documentUrl, "https://example.com/new-doc");
 
       // Check that both spans were recorded (original + redirect)
-      const spans = exporter.getSpans("docloader.fetch");
+      const spans = exporter.getSpans("activitypub.fetch_document");
       assertEquals(spans.length, 2);
 
       // Check the redirect span (last span is the original request that redirected)

packages/fedify/src/runtime/docloader.ts

@@ -360,7 +360,7 @@ export function getDocumentLoader(
     }
 
     return await tracer.startActiveSpan(
-      "docloader.fetch",
+      "activitypub.fetch_document",
       {
         kind: SpanKind.CLIENT,
         attributes: {