fix: reject misrouted smallwebrtc runs on the telephony websocket (#468)

* fix: reject misrouted smallwebrtc runs on the telephony websocket

A smallwebrtc (browser/WebRTC) workflow run is established through the WebRTC
signaling endpoint, not the PSTN telephony websocket. When such a run reached
_handle_telephony_websocket it read no "provider" from initial_context and
closed with an opaque "Provider type not found". Detect smallwebrtc runs and
close with a clear reason pointing to the signaling endpoint, without setting
the run to running or invoking a telephony provider. Also store the provider on
smallwebrtc runs at creation so they are self-describing, and make the generic
no-provider close reason include the run id and mode.

Closes #433

* fix: merge workflow run initial context defaults

---------

Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>
Co-authored-by: Abhishek Kumar <abhishek@a6k.me>

api/tests/test_telephony_routes.py

@@ -1,10 +1,12 @@
 from types import SimpleNamespace
 from unittest.mock import ANY, AsyncMock, Mock, patch
 
+import pytest
 from fastapi import FastAPI
 from fastapi.testclient import TestClient
 
-from api.routes.telephony import router
+from api.enums import WorkflowRunMode, WorkflowRunState
+from api.routes.telephony import _handle_telephony_websocket, router
 from api.services.auth.depends import get_user
 
 
@@ -215,3 +217,41 @@ def test_initiate_call_rejects_existing_run_for_different_workflow():
     mock_db.get_workflow_run.assert_awaited_once_with(501, organization_id=11)
     assert not mock_db.create_workflow_run.called
     assert provider.initiate_call.await_count == 0
+
+
+@pytest.mark.asyncio
+async def test_smallwebrtc_run_reaching_telephony_websocket_closes_without_running():
+    websocket = AsyncMock()
+    workflow_run = SimpleNamespace(
+        id=501,
+        workflow_id=33,
+        mode=WorkflowRunMode.SMALLWEBRTC.value,
+        state=WorkflowRunState.INITIALIZED.value,
+        initial_context={},
+        gathered_context={},
+    )
+    workflow = SimpleNamespace(id=33, organization_id=11)
+    provider_lookup = AsyncMock()
+
+    with (
+        patch("api.routes.telephony.db_client") as mock_db,
+        patch(
+            "api.routes.telephony.get_telephony_provider_for_run",
+            new=provider_lookup,
+        ),
+    ):
+        mock_db.get_workflow_run = AsyncMock(return_value=workflow_run)
+        mock_db.get_workflow_by_id = AsyncMock(return_value=workflow)
+        mock_db.update_workflow_run = AsyncMock()
+
+        await _handle_telephony_websocket(websocket, 33, 99, 501)
+
+    websocket.close.assert_awaited_once_with(
+        code=4400,
+        reason=(
+            "smallwebrtc runs connect through the WebRTC signaling endpoint, "
+            "not the telephony websocket"
+        ),
+    )
+    assert mock_db.update_workflow_run.await_count == 0
+    assert provider_lookup.await_count == 0

api/tests/test_workflow_versioning.py

@@ -606,3 +606,34 @@ class TestRunDefinitionBinding:
         )
 
         assert run.definition_id == draft.id
+
+    async def test_run_initial_context_merges_with_template_context(
+        self, db_session, workflow_with_v1
+    ):
+        """Explicit run context should augment template context, not replace it."""
+        workflow, user = workflow_with_v1
+        await db_session.save_workflow_draft(
+            workflow_id=workflow.id,
+            template_context_variables={
+                "company_name": "Acme",
+                "default_only": "kept",
+            },
+        )
+        await db_session.publish_workflow_draft(workflow.id)
+
+        run = await db_session.create_workflow_run(
+            name="Embed Run",
+            workflow_id=workflow.id,
+            mode="smallwebrtc",
+            user_id=user.id,
+            initial_context={
+                "company_name": "Override Co",
+                "provider": "smallwebrtc",
+            },
+        )
+
+        assert run.initial_context == {
+            "company_name": "Override Co",
+            "default_only": "kept",
+            "provider": "smallwebrtc",
+        }