`kratos-external-idp-integrator` blocked with `Invalid OIDC provider configuration`

**Note: This issue was generated with AI assistance (GitHub Copilot) based on automated log analysis and triage.**

Filed by @canonical/solutions-qa

## Environment

- **Charm under test:** `kratos` r571, channel `latest/edge`
- **Neighbour charm:** `kratos-external-idp-integrator` r299, channel `latest/stable`
- **Supporting charm:** `postgresql-k8s` r774, channel `14/stable`
- **Test plan:** `integration/kratos-external-idp-integrator:kratos-external-idp/external_provider/kratos:kratos-external-idp`
- **Environment:** `juju:3/stable ubuntu:22.04 cmr/kubernetes/openstack`
- **Juju version:** 3.6.21

## What was observed

The `test_deploy` test case fails with a 15-minute `JujuWaitTimeoutError` on the `target` (kratos) unit.

At the time of timeout:
- `neighbour/0` (`kratos-external-idp-integrator`) is in **blocked** state: `Invalid OIDC provider configuration`
- `target/0` (`kratos`) is in **waiting** state: `Waiting for public ingress`

The juju debug log for the neighbour model shows pydantic validation errors starting at the `install` hook:

ERROR unit.neighbor/0.juju-log External IdP provider configuration invalid: 3 validation errors for Providers
0.generic.client_id Field required [type=missing, input_value={'enabled': True, 'provid...et_backend': 'relation'}, input_type=ConfigData]
0.generic.issuer_url Field required [type=missing, input_value={'enabled': True, 'provid...et_backend': 'relation'}, input_type=ConfigData]
0.generic.client_secret Field required [type=missing, input_value={'enabled': True, 'provid...et_backend': 'relation'}, input_type=ConfigData]

The generated neighbor bundle deploys `kratos-external-idp-integrator` with `options: {}` — no OIDC provider credentials are configured.

## Steps to reproduce

1. Run the charm integration test for `kratos` r571 against the `kratos-external-idp/external_provider` test plan in a `cmr/kubernetes/openstack` environment.
2. Observe `kratos-external-idp-integrator` blocking immediately on deploy with `Invalid OIDC provider configuration`.

## Test Observer UI link

https://test-observer.canonical.com/#/charms/407657?testExecutionId=510521&testResultId=11048150

## CI link

https://github.com/canonical/charm-integration-testing/actions/runs/25959595675

## Affected test executions

This failure was observed in at least 3 consecutive test executions: 510497, 510511, 510521 (all for kratos r571).

Start with the integration/kratos-external-idp-integrator:kratos-external-idp/external_provider/kratos:kratos-external-idp test plan and its test_deploy case. Inspect how the generated neighbour bundle handles the kratos-external-idp-integrator options, then rerun the test and confirm the neighbour no longer blocks and the target progresses past waiting for public ingress.

Written by the indexing model from the issue text.