Allow a single repository to trigger PipelineRuns in multiple namespaces on the same cluster

Feature request

PAC currently enforces a one-to-one mapping between a Repository CRD and a namespace. This prevents users from using a single repository to trigger pipelines across multiple namespaces (e.g., different environments) on the same cluster.
This would be a significant quality-of-life improvement for teams managing multi-environment workflows on a single OpenShift cluster using PAC.

Use case

In a typical multi-environment setup on a single cluster, a team may have:

my-app repo
├── triggers pipeline in → namespace: my-app-dev
├── triggers pipeline in → namespace: my-app-staging

Currently this is not possible because PAC only allows one Repository CRD per repository per cluster. Creating multiple Repository CRDs pointing to the same repo in different namespaces is not supported.

Desired Behavior

Allow a single repository to target multiple namespaces, so that:

A push to main could trigger a PipelineRun in my-app-prod
A push to dev could trigger a PipelineRun in my-app-dev
Each namespace can have its own secrets, service accounts, and resource quotas

Current Behavior

Only one Repository CRD is allowed per repository per cluster. Users cannot target different namespaces from the same repository, making multi-environment pipelines on a single cluster impossible with PAC alone.

No files or tests are named. Start by tracing how PAC enforces the one-Repository-per-repository-per-cluster rule and how Repository CRDs select namespaces; then determine the required behavior for branch-specific PipelineRuns with namespace-local secrets, service accounts, and quotas. Done means one repository can trigger PipelineRuns in multiple namespaces on the same cluster.