fix(go-client): use monorepo-compatible module path (#392)

The Go SDK declared its module as github.com/vectorize-io/hindsight-client-go,
but that repository doesn't exist. Update to
github.com/vectorize-io/hindsight/hindsight-clients/go to match the actual
monorepo path, enabling standard `go get` imports with directory-prefixed tags.

Also enables isGoSubmodule in the OpenAPI generator config and updates all
import references across tests, docs, and the client generation script.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: franchb

hindsight-clients/go/README.md

@@ -22,7 +22,7 @@ go get golang.org/x/net/context
 Put the package under your project folder and add the following in import:
 
 ```go
-import hindsight "github.com/vectorize-io/hindsight-client-go"
+import hindsight "github.com/vectorize-io/hindsight/hindsight-clients/go"
 ```
 
 To use a proxy, set the environment variable `HTTP_PROXY`:

hindsight-clients/go/go.mod

@@ -1,4 +1,4 @@
-module github.com/vectorize-io/hindsight-client-go
+module github.com/vectorize-io/hindsight/hindsight-clients/go
 
 go 1.18
 

hindsight-clients/go/openapi-generator-config.yaml

@@ -3,8 +3,8 @@ outputDir: ./
 inputSpec: ../../hindsight-docs/static/openapi.json
 packageName: hindsight
 gitUserId: vectorize-io
-gitRepoId: hindsight-client-go
-isGoSubmodule: false
+gitRepoId: hindsight/hindsight-clients/go
+isGoSubmodule: true
 enumClassPrefix: true
 structPrefix: true
 generateInterfaces: true