Add Helm chart for paperless-ai document management system

This commit introduces a new Helm chart for deploying paperless-ai, an AI-
 enhanced document management system based on paperless-ngx. The chart
 includes:

 - Complete deployment configuration with configurable replicas
 - Persistent volume support for data storage
 - Secret management for API tokens and keys
 - Environment variable configuration via ConfigMaps and Secrets
 - Ingress configuration options
 - Support for both OpenAI and Ollama AI providers
 - Customizable system prompts and document processing settings
 - CI workflow for automated chart packaging and publishing

 The chart enables Kubernetes users to easily deploy and configure the
 paperless-ai system with proper separation of configuration and secrets.

.gitea/workflows/build-chart-paperless-ai.yml

@@ -0,0 +1,43 @@
+name: "Build Helm Chart"
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - "charts/paperless-ai/Chart.yaml"
+
+jobs:
+  helm-package:
+    runs-on: ubuntu-latest
+    env:
+      APP: charts/paperless-ai
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Set Helm Chart App Name and Version
+        id: get_version
+        run: |
+          APP_NAME=$(grep -oP '(?<=^name: ).*' ${{ env.APP }}/Chart.yaml)
+          echo "Helm Chart App Name: $APP_NAME"
+          echo "::set-output name=app::$APP_NAME"
+
+          CHART_VERSION=$(grep -oP '(?<=^version: ).*' ${{ env.APP }}/Chart.yaml)
+          echo "Helm Chart version: $CHART_VERSION"
+          echo "::set-output name=tag::$CHART_VERSION"
+
+      - name: Setup Helm
+        run: |
+          #curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash
+          curl -kSso /usr/local/bin/helm https://debmirror.cooltux.net/helm-v3.18.3 && chmod +x /usr/local/bin/helm
+          helm version
+
+      - name: Package Helm Chart
+        run: |
+          helm dependency update ${{ env.APP }}
+          helm lint ${{ env.APP }}
+          helm package ${{ env.APP }}
+
+      - name: Upload Helm Package to repo
+        run: |
+          curl --user ${{ secrets.USER }}:${{ secrets.TOKEN }} -X POST --upload-file ./${{ steps.get_version.outputs.app }}-${{ steps.get_version.outputs.tag }}.tgz ${{ vars.HELMREGISTRY }}/api/packages/${{ vars.OWNER }}/helm/api/charts