gnd: Replace custom manifest parsing with graph-node types

Replace gnd's lenient manual JSON/YAML parsing with graph-node's
`UnresolvedSubgraphManifest<Chain>::parse()`. This uses the same serde
types as graph-node itself, so required fields like `source.abi` and
`mapping.abis` are now enforced at parse time.

Changes:
- Add `graph-chain-ethereum` as a direct gnd dependency
- Rewrite `load_manifest()` to use `UnresolvedSubgraphManifest::parse()`
- Convert parsed graph-node types into gnd's existing Manifest/DataSource
  /Template/Abi types to minimize caller changes
- Re-export unresolved Ethereum types from graph-chain-ethereum for future
  validation steps
- Add `UnresolvedSource::address()` accessor on subgraph data sources
- Add tests for missing `source.abi` and missing `mapping.abis` rejection
- Update test manifests to include all required fields

Author: lutter

Cargo.lock

@@ -23,7 +23,9 @@ pub use buffered_call_cache::BufferedCallCache;
 
 // ETHDEP: These concrete types should probably not be exposed.
 pub use data_source::{
-    BlockHandlerFilter, DataSource, DataSourceTemplate, Mapping, TemplateSource,
+    BlockHandlerFilter, DataSource, DataSourceTemplate, Mapping, MappingBlockHandler,
+    MappingCallHandler, TemplateSource, UnresolvedDataSource, UnresolvedDataSourceTemplate,
+    UnresolvedMapping, UnresolvedMappingEventHandler,
 };
 
 pub mod chain;

chain/ethereum/src/lib.rs

@@ -18,6 +18,7 @@ path = "tests/codegen_verification.rs"
 [dependencies]
 # Core graph dependencies
 graph = { path = "../graph" }
+graph-chain-ethereum = { path = "../chain/ethereum" }
 graph-core = { path = "../core" }
 graph-node = { path = "../node" }
 

gnd/Cargo.toml

@@ -612,6 +612,8 @@ schema:
 dataSources:
   - kind: ethereum/contract
     name: TestDataSource
+    source:
+      abi: TestContract
     mapping:
       kind: ethereum/events
       apiVersion: 0.0.5
@@ -727,6 +729,8 @@ schema:
 dataSources:
   - kind: ethereum/contract
     name: ExampleSubgraph
+    source:
+      abi: ExampleContract
     mapping:
       kind: ethereum/events
       apiVersion: 0.0.5