Clean up Helm chart for Python backend

- Remove configmap.yaml (Python uses env vars, not YAML config)
- Remove migration-job.yaml (SQLAlchemy creates tables on startup)
- Rename migrations.enabled to waitForDatabase
- Set readOnlyRootFilesystem: false (Python needs __pycache__)

helm/orchard/templates/deployment.yaml

@@ -14,7 +14,6 @@ spec:
   template:
     metadata:
       annotations:
-        checksum/config: {{ include (print $.Template.BasePath "/configmap.yaml") . | sha256sum }}
         checksum/secret: {{ include (print $.Template.BasePath "/secret.yaml") . | sha256sum }}
       {{- with .Values.podAnnotations }}
         {{- toYaml . | nindent 8 }}
@@ -33,7 +32,7 @@ spec:
       securityContext:
         {{- toYaml .Values.podSecurityContext | nindent 8 }}
       initContainers:
-        {{- if .Values.migrations.enabled }}
+        {{- if .Values.waitForDatabase }}
         - name: wait-for-db
           image: "{{ .Values.initContainer.image.repository }}:{{ .Values.initContainer.image.tag }}"
           imagePullPolicy: {{ .Values.initContainer.image.pullPolicy }}