refactor: move Helm chart to standard directory structure

This commit restructures the paperless-ai Helm chart by moving all files
 from the nested directory (charts/paperless-ai/paperless-ai/) to the
 standard Helm chart directory structure (charts/paperless-ai/). The change
 eliminates the redundant directory nesting that was causing issues with
 Helm chart packaging and installation. No functional changes were made to
 any files - this is purely a directory structure reorganization to follow
 Helm best practices and improve chart maintainability.

charts/paperless-ai/templates/tests/test-connection.yaml

@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: "{{ include "paperless-ai.fullname" . }}-test-connection"
+  labels:
+    {{- include "paperless-ai.labels" . | nindent 4 }}
+  annotations:
+    "helm.sh/hook": test
+spec:
+  containers:
+    - name: wget
+      image: busybox
+      command: ['wget']
+      args: ['{{ include "paperless-ai.fullname" . }}:{{ .Values.service.port }}']
+  restartPolicy: Never