Add connection management API endpoints and models (#65)

## Summary

Introduces a complete connection management module to the
`robosystems_client`, providing full CRUD operations and OAuth support
for external data provider connections. This feature adds 8 new API
endpoints and 20+ supporting model definitions, along with a minor
update to the existing `DownloadQuota` model.

## Key Accomplishments

### New API Endpoints (`api/connections/`)
- **Create Connection** – Establish new connections to external
providers
- **Delete Connection** – Remove existing connections
- **Get Connection** – Retrieve details for a specific connection
- **Get Connection Options** – Fetch available configuration options for
providers
- **List Connections** – Query and filter all connections with provider
type filtering
- **Init OAuth** – Initiate OAuth authentication flows with configurable
additional params
- **OAuth Callback** – Handle OAuth redirect callbacks to complete
authentication
- **Sync Connection** – Trigger data synchronization on a connection
with customizable sync options

### New Models
- **Connection models**: `ConnectionResponse`,
`ConnectionResponseMetadata`, `ConnectionOptionsResponse`,
`ConnectionProviderInfo` (with auth type and provider enums)
- **Request models**: `CreateConnectionRequest`, `OAuthInitRequest`,
`OAuthCallbackRequest`, `SyncConnectionRequest`
- **Response models**: `OAuthInitResponse`,
`SyncConnectionResponseSyncconnection`
- **Provider-specific configs**: `PlaidConnectionConfig` (with accounts
and institution types), `QuickBooksConnectionConfig`,
`SecConnectionConfig`
- **Supporting types**: `ListConnectionsProviderType0`,
`CreateConnectionRequestProvider`,
`OAuthInitRequestAdditionalParamsType0`,
`SyncConnectionRequestSyncOptionsType0`

### Modified Models
- **`DownloadQuota`** – Updated attribute definitions (28 lines changed,
likely field type or naming adjustments)
- **`models/__init__.py`** – Updated to export all new model classes

## Breaking Changes

- The `DownloadQuota` model has been modified. Consumers relying on its
previous attribute structure should verify compatibility after
upgrading.

## Testing Notes

- Verify each of the 8 connection API endpoints for correct request
serialization and response deserialization
- Test OAuth flow end-to-end (init → callback) to ensure proper state
handling
- Validate provider-specific configurations (Plaid, QuickBooks, SEC)
with realistic payloads
- Confirm `DownloadQuota` changes do not regress existing functionality
that depends on this model
- Test `list_connections` filtering by provider type, including
union/optional type handling

## Infrastructure Considerations

- This is a client-side SDK change; no backend deployment is required,
but the corresponding API endpoints must be available on the target
environment
- New provider integrations (Plaid, QuickBooks, SEC) may require
environment-specific credentials and OAuth redirect URI configuration
- The OAuth callback endpoint implies a redirect flow — ensure client
applications have appropriate callback handling in place

---
🤖 Generated with [Claude Code](https://claude.ai/code)

**Branch Info:**
- Source: `feature/connection-management`
- Target: `main`
- Type: feature

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jfrench9

robosystems_client/api/connections/__init__.py

@@ -0,0 +1 @@
+"""Contains endpoint functions for accessing the API"""

robosystems_client/api/connections/create_connection.py

@@ -0,0 +1,291 @@
+from http import HTTPStatus
+from typing import Any
+from urllib.parse import quote
+
+import httpx
+
+from ... import errors
+from ...client import AuthenticatedClient, Client
+from ...models.connection_response import ConnectionResponse
+from ...models.create_connection_request import CreateConnectionRequest
+from ...models.error_response import ErrorResponse
+from ...models.http_validation_error import HTTPValidationError
+from ...types import Response
+
+
+def _get_kwargs(
+  graph_id: str,
+  *,
+  body: CreateConnectionRequest,
+) -> dict[str, Any]:
+  headers: dict[str, Any] = {}
+
+  _kwargs: dict[str, Any] = {
+    "method": "post",
+    "url": "/v1/graphs/{graph_id}/connections".format(
+      graph_id=quote(str(graph_id), safe=""),
+    ),
+  }
+
+  _kwargs["json"] = body.to_dict()
+
+  headers["Content-Type"] = "application/json"
+
+  _kwargs["headers"] = headers
+  return _kwargs
+
+
+def _parse_response(
+  *, client: AuthenticatedClient | Client, response: httpx.Response
+) -> ConnectionResponse | ErrorResponse | HTTPValidationError | None:
+  if response.status_code == 201:
+    response_201 = ConnectionResponse.from_dict(response.json())
+
+    return response_201
+
+  if response.status_code == 400:
+    response_400 = ErrorResponse.from_dict(response.json())
+
+    return response_400
+
+  if response.status_code == 403:
+    response_403 = ErrorResponse.from_dict(response.json())
+
+    return response_403
+
+  if response.status_code == 409:
+    response_409 = ErrorResponse.from_dict(response.json())
+
+    return response_409
+
+  if response.status_code == 422:
+    response_422 = HTTPValidationError.from_dict(response.json())
+
+    return response_422
+
+  if response.status_code == 500:
+    response_500 = ErrorResponse.from_dict(response.json())
+
+    return response_500
+
+  if client.raise_on_unexpected_status:
+    raise errors.UnexpectedStatus(response.status_code, response.content)
+  else:
+    return None
+
+
+def _build_response(
+  *, client: AuthenticatedClient | Client, response: httpx.Response
+) -> Response[ConnectionResponse | ErrorResponse | HTTPValidationError]:
+  return Response(
+    status_code=HTTPStatus(response.status_code),
+    content=response.content,
+    headers=response.headers,
+    parsed=_parse_response(client=client, response=response),
+  )
+
+
+def sync_detailed(
+  graph_id: str,
+  *,
+  client: AuthenticatedClient,
+  body: CreateConnectionRequest,
+) -> Response[ConnectionResponse | ErrorResponse | HTTPValidationError]:
+  """Create Connection
+
+   Create a new data connection for external system integration.
+
+  This endpoint initiates connections to external data sources:
+
+  **SEC Connections**:
+  - Provide entity CIK for automatic filing retrieval
+  - No authentication needed
+  - Begins immediate data sync
+
+  **QuickBooks Connections**:
+  - Returns OAuth URL for authorization
+  - Requires admin permissions in QuickBooks
+  - Complete with OAuth callback
+
+  **Plaid Connections**:
+  - Returns Plaid Link token
+  - User completes bank authentication
+  - Exchange public token for access
+
+  Note:
+  This operation is included - no credit consumption required.
+
+  Args:
+      graph_id (str):
+      body (CreateConnectionRequest): Request to create a new connection.
+
+  Raises:
+      errors.UnexpectedStatus: If the server returns an undocumented status code and Client.raise_on_unexpected_status is True.
+      httpx.TimeoutException: If the request takes longer than Client.timeout.
+
+  Returns:
+      Response[ConnectionResponse | ErrorResponse | HTTPValidationError]
+  """
+
+  kwargs = _get_kwargs(
+    graph_id=graph_id,
+    body=body,
+  )
+
+  response = client.get_httpx_client().request(
+    **kwargs,
+  )
+
+  return _build_response(client=client, response=response)
+
+
+def sync(
+  graph_id: str,
+  *,
+  client: AuthenticatedClient,
+  body: CreateConnectionRequest,
+) -> ConnectionResponse | ErrorResponse | HTTPValidationError | None:
+  """Create Connection
+
+   Create a new data connection for external system integration.
+
+  This endpoint initiates connections to external data sources:
+
+  **SEC Connections**:
+  - Provide entity CIK for automatic filing retrieval
+  - No authentication needed
+  - Begins immediate data sync
+
+  **QuickBooks Connections**:
+  - Returns OAuth URL for authorization
+  - Requires admin permissions in QuickBooks
+  - Complete with OAuth callback
+
+  **Plaid Connections**:
+  - Returns Plaid Link token
+  - User completes bank authentication
+  - Exchange public token for access
+
+  Note:
+  This operation is included - no credit consumption required.
+
+  Args:
+      graph_id (str):
+      body (CreateConnectionRequest): Request to create a new connection.
+
+  Raises:
+      errors.UnexpectedStatus: If the server returns an undocumented status code and Client.raise_on_unexpected_status is True.
+      httpx.TimeoutException: If the request takes longer than Client.timeout.
+
+  Returns:
+      ConnectionResponse | ErrorResponse | HTTPValidationError
+  """
+
+  return sync_detailed(
+    graph_id=graph_id,
+    client=client,
+    body=body,
+  ).parsed
+
+
+async def asyncio_detailed(
+  graph_id: str,
+  *,
+  client: AuthenticatedClient,
+  body: CreateConnectionRequest,
+) -> Response[ConnectionResponse | ErrorResponse | HTTPValidationError]:
+  """Create Connection
+
+   Create a new data connection for external system integration.
+
+  This endpoint initiates connections to external data sources:
+
+  **SEC Connections**:
+  - Provide entity CIK for automatic filing retrieval
+  - No authentication needed
+  - Begins immediate data sync
+
+  **QuickBooks Connections**:
+  - Returns OAuth URL for authorization
+  - Requires admin permissions in QuickBooks
+  - Complete with OAuth callback
+
+  **Plaid Connections**:
+  - Returns Plaid Link token
+  - User completes bank authentication
+  - Exchange public token for access
+
+  Note:
+  This operation is included - no credit consumption required.
+
+  Args:
+      graph_id (str):
+      body (CreateConnectionRequest): Request to create a new connection.
+
+  Raises:
+      errors.UnexpectedStatus: If the server returns an undocumented status code and Client.raise_on_unexpected_status is True.
+      httpx.TimeoutException: If the request takes longer than Client.timeout.
+
+  Returns:
+      Response[ConnectionResponse | ErrorResponse | HTTPValidationError]
+  """
+
+  kwargs = _get_kwargs(
+    graph_id=graph_id,
+    body=body,
+  )
+
+  response = await client.get_async_httpx_client().request(**kwargs)
+
+  return _build_response(client=client, response=response)
+
+
+async def asyncio(
+  graph_id: str,
+  *,
+  client: AuthenticatedClient,
+  body: CreateConnectionRequest,
+) -> ConnectionResponse | ErrorResponse | HTTPValidationError | None:
+  """Create Connection
+
+   Create a new data connection for external system integration.
+
+  This endpoint initiates connections to external data sources:
+
+  **SEC Connections**:
+  - Provide entity CIK for automatic filing retrieval
+  - No authentication needed
+  - Begins immediate data sync
+
+  **QuickBooks Connections**:
+  - Returns OAuth URL for authorization
+  - Requires admin permissions in QuickBooks
+  - Complete with OAuth callback
+
+  **Plaid Connections**:
+  - Returns Plaid Link token
+  - User completes bank authentication
+  - Exchange public token for access
+
+  Note:
+  This operation is included - no credit consumption required.
+
+  Args:
+      graph_id (str):
+      body (CreateConnectionRequest): Request to create a new connection.
+
+  Raises:
+      errors.UnexpectedStatus: If the server returns an undocumented status code and Client.raise_on_unexpected_status is True.
+      httpx.TimeoutException: If the request takes longer than Client.timeout.
+
+  Returns:
+      ConnectionResponse | ErrorResponse | HTTPValidationError
+  """
+
+  return (
+    await asyncio_detailed(
+      graph_id=graph_id,
+      client=client,
+      body=body,
+    )
+  ).parsed