fix(helm): add shared volume support for docreader artifacts

[lordk911]

Summary

This PR adds configurable shared volume support to the Helm chart, aligning it with the docker-compose.yml configuration.

Problem

The docker-compose.yml shares a docreader-tmp volume between:

• docreader service (read-write at /tmp/docreader) — writes extracted images during document parsing
• app service (read-only at /tmp/docreader) — reads images for display and VLM analysis

This shared volume configuration was missing from the Helm chart:

• docreader.yaml had no volumes or volumeMounts at all
• app.yaml only had data-files volume, no docreader-tmp mount

This caused document parsing with image extraction to fail in Kubernetes deployments using the Helm chart.

Solution

Added configurable docreader.sharedVolume support:

1. values.yaml

docreader:
  sharedVolume:
    enabled: true
    type: emptyDir  # or "pvc" for production multi-node
    sizeLimit: 5Gi  # for emptyDir
    pvcName: ""     # for PVC (auto-generated if empty)
    storageClass: ""
    size: 5Gi       # for PVC

2. docreader.yaml

Added volumeMount (/tmp/docreader, read-write) and volume definition.

3. app.yaml

Added volumeMount (/tmp/docreader, read-only) and volume definition.

Usage Examples

Single-node / Testing (emptyDir, default)

docreader:
  sharedVolume:
    type: emptyDir
    sizeLimit: 5Gi

Production / Multi-node (PVC with ReadWriteMany)

docreader:
  sharedVolume:
    type: pvc
    pvcName: weknora-docreader-tmp  # pre-created cephfs/NFS PVC

Or let the chart create the PVC:

docreader:
  sharedVolume:
    type: pvc
    storageClass: rook-cephfs  # or nfs, etc.
    size: 10Gi

Testing

• ✅ Templates render correctly with both emptyDir and pvc configurations
• ✅ Backward compatible: default emptyDir works for single-node testing
• ✅ Production-ready: supports ReadWriteMany PVCs (cephfs, NFS, etc.)

Related

• Aligns Helm chart with docker-compose.yml behavior
• Fixes document parsing with image extraction in Kubernetes deployments

[lyingbug]

Default emptyDir cannot share data between app and docreader, so default sharedVolume.enabled should be flase ?

[lyingbug]

this file should be removed

[lyingbug]

PVC auto-creation is documented but not implemented

[lordk911]

Thanks for the review @lyingbug! All three points addressed in the latest push:

1. Default sharedVolume.enabled → false (helm/values.yaml)
You're right — emptyDir is pod-scoped and cannot share data between the app and docreader Deployments (separate pods). Changed the default to false for backward compatibility, and updated the comments to make this limitation explicit. Users who need cross-pod sharing must set enabled: true + type: pvc with a ReadWriteMany storage class.

2. Removed WeKnora部署讨论记录.md from this PR
Rebuilt the branch to contain only the Helm chart changes. That file was a personal deployment note and shouldn't be here.

3. Implemented PVC auto-creation (helm/templates/docreader-pvc.yaml)
Added the missing template that creates a PVC when type: pvc and pvcName is empty. Also added an accessMode config (defaults to ReadWriteMany) so users can control the access mode of the auto-created PVC.

The branch is now focused solely on the Helm chart shared-volume fix (2 commits). Please take another look when you have time.