feat: billing and credit management v2 (#429)

* feat: use mps generated correlation ID

* chore: update pipecat submodule

* feat: add credit purchase URL

* feat: carve out billing page and show credit ledger

* feat: deprecate dograh based quota tracking

* fix: remove cost calculation from dograh codebase

* fix: create mps account on migrate to v2

* chore: update pipecat

api/tests/test_auth_depends.py

@@ -0,0 +1,68 @@
+from types import SimpleNamespace
+from unittest.mock import AsyncMock
+
+import pytest
+
+from api.services.auth import depends as auth_depends
+
+
+@pytest.mark.asyncio
+async def test_get_user_initializes_hosted_mps_billing_for_new_org(monkeypatch):
+    stack_user = {
+        "id": "stack-user-1",
+        "selected_team_id": "team-1",
+        "primary_email_verified": False,
+    }
+    user = SimpleNamespace(
+        id=7,
+        email=None,
+        provider_id="stack-user-1",
+        selected_organization_id=None,
+    )
+    organization = SimpleNamespace(id=42)
+    existing_config = SimpleNamespace(llm=object(), tts=None, stt=None)
+
+    ensure_billing = AsyncMock(return_value={"billing_mode": "v2"})
+
+    monkeypatch.setattr(auth_depends, "AUTH_PROVIDER", "stack")
+    monkeypatch.setattr(
+        auth_depends.stackauth,
+        "get_user",
+        AsyncMock(return_value=stack_user),
+    )
+    monkeypatch.setattr(
+        auth_depends.db_client,
+        "get_or_create_user_by_provider_id",
+        AsyncMock(return_value=(user, False)),
+    )
+    monkeypatch.setattr(
+        auth_depends.db_client,
+        "get_or_create_organization_by_provider_id",
+        AsyncMock(return_value=(organization, True)),
+    )
+    monkeypatch.setattr(
+        auth_depends.db_client,
+        "add_user_to_organization",
+        AsyncMock(),
+    )
+    monkeypatch.setattr(
+        auth_depends.db_client,
+        "update_user_selected_organization",
+        AsyncMock(),
+    )
+    monkeypatch.setattr(
+        auth_depends.db_client,
+        "get_user_configurations",
+        AsyncMock(return_value=existing_config),
+    )
+    monkeypatch.setattr(
+        auth_depends,
+        "ensure_hosted_mps_billing_account_v2",
+        ensure_billing,
+    )
+
+    result = await auth_depends.get_user(authorization="Bearer token")
+
+    assert result is user
+    assert result.selected_organization_id == 42
+    ensure_billing.assert_awaited_once_with(42, created_by="stack-user-1")