HIP-1137: Block Node discoverability via on-chain registry

[Dosik13]

Description:

Add support for HIP-1137.

• Add BlockNodeApi enum with well-known block node API kinds (OTHER, STATUS, PUBLISH, SUBSCRIBE_STREAM, STATE_PROOF)
• Add RegisteredServiceEndpoint interface with registeredEndpointBase shared struct for common endpoint fields (IP/domain, port, TLS)
• Add BlockNodeServiceEndpoint, MirrorNodeServiceEndpoint, RpcRelayServiceEndpoint, and GeneralServiceEndpoint as concrete endpoint subtypes with protobuf round-trip support
• Add RegisteredNodeCreateTransaction for creating registered nodes with admin key, description, and service endpoints
• Add RegisteredNodeUpdateTransaction for updating registered node description, admin key, and service endpoints
• Add RegisteredNodeDeleteTransaction for removing registered nodes from the address book
• Wire all three registered-node transactions into SchedulableTransactionBody so they can be scheduled via ScheduleCreateTransaction
• Add RegisteredNodeAddressBookQuery (REST against the mirror node) along with RegisteredNode and RegisteredNodeAddressBook result types — supports SetRegisteredNodeId filtering and SetLimit page size
• Add RegisteredNodeId field to TransactionReceipt
• Add new response status codes (INVALID_REGISTERED_NODE_ID, INVALID_REGISTERED_ENDPOINT, REGISTERED_ENDPOINTS_EXCEEDED_LIMIT, INVALID_REGISTERED_ENDPOINT_ADDRESS, INVALID_REGISTERED_ENDPOINT_TYPE, REGISTERED_NODE_STILL_ASSOCIATED, MAX_REGISTERED_NODES_EXCEEDED)
• Add associatedRegisteredNodes field to NodeCreateTransaction with setter and getter
• Add associatedRegisteredNodes field to NodeUpdateTransaction with Set/Add/Clear/Get methods (three-state semantics: nil = unchanged, empty = clear, non-empty = replace)
• Add examples/registered_node/main.go walking through the full lifecycle
• Add unit tests for all new types and transactions including mock server, protobuf round-trip, coverage, and serialization tests
• Add e2e tests covering the test plan**, with mirror-node verification on every success-path test**
• Fix record/receipt query unit tests that need the new registeredNodeId field
• Add constants.go and extract shared "UNKNOWN" string literal to fix goconst lint warning

Related issue(s):

Fixes #1634

Notes for reviewer:

Checklist

• Documented (Code comments, README, etc.)
• Tested (unit, integration, etc.)

[lfdt-bot]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues

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[codecov]

Codecov Report

❌ Patch coverage is 89.53488% with 72 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
sdk/registered_node_address_book_query.go	79.67%	23 Missing and 15 partials ⚠️
sdk/transaction.go	33.33%	12 Missing ⚠️
sdk/node_update_transaction.go	74.35%	9 Missing and 1 partial ⚠️
sdk/node_create_transaction.go	81.81%	4 Missing ⚠️
sdk/registered_node_delete_transaction.go	95.55%	1 Missing and 1 partial ⚠️
sdk/registered_node_update_transaction.go	97.75%	1 Missing and 1 partial ⚠️
sdk/transaction_receipt.go	81.81%	1 Missing and 1 partial ⚠️
sdk/block_node_api.go	96.29%	1 Missing ⚠️
sdk/registered_service_endpoint.go	98.14%	1 Missing ⚠️

Files with missing lines	Coverage Δ
sdk/block_node_service_endpoint.go	100.00% <100.00%> (ø)
sdk/fee_estimate_types.go	100.00% <100.00%> (ø)
sdk/general_service_endpoint.go	100.00% <100.00%> (ø)
sdk/mirror_node_service_endpoint.go	100.00% <100.00%> (ø)
sdk/registered_node_create_transaction.go	100.00% <100.00%> (ø)
sdk/rpc_relay_service_endpoint.go	100.00% <100.00%> (ø)
sdk/status.go	99.87% <100.00%> (ø)
sdk/block_node_api.go	96.29% <96.29%> (ø)
sdk/registered_service_endpoint.go	98.14% <98.14%> (ø)
sdk/registered_node_delete_transaction.go	95.55% <95.55%> (ø)
... and 6 more

... and 71 files with indirect coverage changes

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[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

View in Codacy

🟢 Metrics 372 complexity · 356 duplication

Metric	Results
Complexity	372
Duplication	356

View in Codacy

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[kaldun-tech]

Hi @Dosik13 @0xivanov

I've been following the repo. Would love to contribute a code review pass. Looks like there's a coverage gap with transaction.go (28.57%) I could improve on if you like.

[ivaylonikolov7]

blockNodeApiFromString silently maps unknowns to BlockNodeApiOther. That can mask a future endpoint_apis value the SDK doesn't yet know about.

[ivaylonikolov7]

When TransactionReceipt.RegisteredNodeId is nil when the proto value is absent you map it to 0. I think you should map it to nil so user is not confused when he sees node id 0. Our users might not know that there is no consensus node id 0.

[gstoykow]

LGTM.