Initial commit: Pezkuwi SubQuery indexer

- pezkuwi.yaml: Relay chain staking indexer (rewards, slashes, pools, transfers, era info)
- pezkuwi-assethub.yaml: Asset Hub indexer (NominationPools, asset transfers)
- GraphQL schema for staking data entities
- Handler mappings from Nova SubQuery base

docker/init/create_extension.sql

@@ -0,0 +1 @@
+CREATE EXTENSION IF NOT EXISTS btree_gist;

docker/subql-node-Dockerfile

@@ -0,0 +1,12 @@
+ARG NODE_JS_IMAGE_VERSION=20-alpine
+ARG SUBQL_NODE_IMAGE_VERSION=v5.6.0
+
+FROM node:${NODE_JS_IMAGE_VERSION} AS build
+
+ADD . /project
+WORKDIR /project
+RUN yarn install && yarn codegen && yarn build
+
+FROM onfinality/subql-node:${SUBQL_NODE_IMAGE_VERSION}
+
+COPY --from=build /project /project