feat: add multichain support to endpoint resource

Adds an optional `multichain` boolean attribute to the `quicknode_endpoint`
resource. Wires the QuickNode Admin API enable_multichain and
disable_multichain endpoints into Create/Update, and reads the current
state back via the `is_multichain` field on the show endpoint response so
drift is detected.

Side effects from `make vendor`:
- Refresh of api/quicknode/openapi.json and the generated client, which
  adds `is_multichain` (plus other new fields like `name`, `is_dedicated`,
  `is_flat_rate`, `status`) to the endpoint types.
- Refresh of api/streams/streams-openapi.json and the generated client.
- Local rename of a duplicate `deleteTag` operationId (two different paths
  upstream share the same id) to unblock code generation.

Tests:
- Unit tests for the new setMultichain helper covering enable/disable
  success, transport errors, and non-200 responses.

Author: andreclaro

GNUmakefile

@@ -14,7 +14,14 @@ CURL_FLAGS := --fail --retry 5 --retry-max-time 120 --retry-connrefused -s
 
 .PHONY: vendor
 vendor:
-	curl $(CURL_FLAGS) https://www.quicknode.com/api-docs/v0/swagger.json  | jq . > api/quicknode/openapi.json
+	# The upstream QuickNode spec reuses the `deleteTag` operationId for two
+	# distinct paths (`/v0/endpoints/{id}/tags/{tag_id}` and
+	# `/v0/endpoints/tags/{id}`), which trips up oapi-codegen. Rename the
+	# account-level op locally to `deleteAccountTag` until QuickNode fixes
+	# this upstream; remove the jq step once they do.
+	curl $(CURL_FLAGS) https://www.quicknode.com/api-docs/v0/swagger.json \
+		| jq '.paths."/v0/endpoints/tags/{id}".delete.operationId = "deleteAccountTag"' \
+		> api/quicknode/openapi.json
 	curl $(CURL_FLAGS) https://api.quicknode.com/streams/rest/openapi.json | jq . > api/streams/streams-openapi.json
 	go generate ./api/...