Enhance Availability with a PodDisruptionBudget (PDB) via chart

[dbrrt]

The current Helm chart deployment does not include a PodDisruptionBudget (PDB).

PDBs are essential for maintaining the availability of an application by defining the minimum number or percentage of replicas that must be available at any given time. Without one, voluntary disruptions (e.g., draining nodes during maintenance, cluster autoscaler downsizes) could lead to the service being temporarily unavailable.

To improve application resilience and operational safety, I propose adding a default PDB resource to the chart.