feat: refactor union types to use discriminated dispatch and add new providers

Overhaul the assistant-related union types (AssistantCredentialsItem,
AssistantModel, AssistantTranscriber, AssistantVoice, and their
UpdateAssistantDto counterparts) to use a provider-discriminated pattern
instead of try-each untagged deserialization. All union struct fields are
renamed from verbose DTO names (e.g. CreateElevenLabsCredentialDto) to
short provider-keyed names (e.g. Field11Labs), and all Visitor interface
methods are renamed accordingly (e.g. VisitCreateElevenLabsCredentialDto
→ VisitField11Labs).

Key changes:
- All union types now expose a `Provider` string discriminant field and use
  `internal.MarshalJSONWithExtraProperty` for serialization, ensuring the
  provider tag is always present on the wire
- Renamed exported struct fields and Visitor methods across
  AssistantCredentialsItem, AssistantModel, AssistantTranscriber,
  AssistantVoice, UpdateAssistantDtoCredentialsItem,
  UpdateAssistantDtoModel, UpdateAssistantDtoTranscriber, and
  UpdateAssistantDtoVoice — existing callers must update field access and
  Visitor implementations
- New credential providers added: AnthropicBedrock, Soniox, Wellsaid,
  Email, SlackWebhook; new model providers: AnthropicBedrock, Minimax;
  new transcriber providers: Soniox; new voice providers: Wellsaid
- New enum constants AssistantClientMessagesItemAssistantSpeechStarted,
  AssistantServerMessagesItemAssistantSpeechStarted, and their
  UpdateAssistantDto counterparts
- SessionCreatedHook added to AssistantHooksItem and
  UpdateAssistantDtoHooksItem unions
- Metadata field type changed from map[string]interface{} to map[string]any
  (source-compatible in Go 1.18+)
- Nil-guard and String() nil checks added to Assistant methods
- UpdateAssistantDto gains explicit MarshalJSON/UnmarshalJSON methods

🌿 Generated with Fern

Author: fern-api[bot]

.fern/metadata.json

@@ -0,0 +1,10 @@
+{
+  "cliVersion": "4.63.4",
+  "generatorName": "fernapi/fern-go-sdk",
+  "generatorVersion": "1.32.1",
+  "generatorConfig": {
+    "union": "v1"
+  },
+  "originGitCommit": "7ba38da97d0e48c7157051761284febe129e15c6",
+  "sdkVersion": "v1.0.0"
+}

.fernignore

@@ -1,3 +1,4 @@
 # Specify files that shouldn't be modified by Fern
 
 README.md
+changelog.md

.github/workflows/ci.yml

@@ -2,6 +2,10 @@ name: ci
 
 on: [push]
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: false
+
 jobs:
   compile:
     runs-on: ubuntu-latest
@@ -14,6 +18,19 @@ jobs:
 
       - name: Compile
         run: go build ./...
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Set up go
+        uses: actions/setup-go@v4
+
+      - name: Lint
+        uses: golangci/golangci-lint-action@v9
+        with:
+          version: v2.10.1
   test:
     runs-on: ubuntu-latest
     steps:
@@ -23,5 +40,23 @@ jobs:
       - name: Set up go
         uses: actions/setup-go@v4
 
+      - name: Setup wiremock server
+        run: |
+          PROJECT_NAME="wiremock-$(basename $(dirname $(pwd)) | tr -d '.')"
+          echo "PROJECT_NAME=$PROJECT_NAME" >> $GITHUB_ENV
+          if [ -f wiremock/docker-compose.test.yml ]; then
+            docker compose -p "$PROJECT_NAME" -f wiremock/docker-compose.test.yml down
+            docker compose -p "$PROJECT_NAME" -f wiremock/docker-compose.test.yml up -d
+            WIREMOCK_PORT=$(docker compose -p "$PROJECT_NAME" -f wiremock/docker-compose.test.yml port wiremock 8080 | cut -d: -f2)
+            echo "WIREMOCK_URL=http://localhost:$WIREMOCK_PORT" >> $GITHUB_ENV
+          fi
+
       - name: Test
         run: go test ./...
+
+      - name: Teardown wiremock server
+        if: always()
+        run: |
+          if [ -f wiremock/docker-compose.test.yml ]; then
+            docker compose -p "$PROJECT_NAME" -f wiremock/docker-compose.test.yml down
+          fi