diff --git a/docs/architecture/storage.md b/docs/architecture/storage.md
index de0b2111..22ddf9a0 100644
--- a/docs/architecture/storage.md
+++ b/docs/architecture/storage.md
@@ -289,11 +289,43 @@ nfsiostat 5
 1. Move hot data to SSD NFS: relocate from `/srv/nfs/<service>` to `/srv/nfs-ssd/<service>` and update PV path
 2. Tune NFS mount: add `rsize=1048576,wsize=1048576` to StorageClass `mountOptions`
 
+## Nextcloud as PVE-NFS browser
+
+Both NFS export roots are mounted into the Nextcloud server pod — `/srv/nfs` at `/mnt/pve-nfs` and `/srv/nfs-ssd` at `/mnt/pve-nfs-ssd` — via standard NFS PVs (`nfs_volume` module). No host-level Unix user/group setup; Nextcloud is the sole household-facing surface.
+
+**ACL model — two patterns:**
+
+- **Root browser mounts** (`PVE NFS Pool`, `PVE NFS-SSD Pool`): scoped to NC group `admin`. Used by Viktor for ad-hoc browsing of any cluster NFS state. Other users never see these mounts.
+- **Per-archive mounts** (e.g. `/anca-elements` → `/mnt/pve-nfs/anca-elements`): one NC External mount per archive, `applicable_users` set to the archive owners. Users see only the mounts assigned to them. Write/delete access is implicit at the OS level (NC pod writes via `no_root_squash`); deny semantics come from mount visibility — if the mount is not in your list, you cannot reach the path.
+
+**Why mount-level ACL, not Files Access Control**: NC 30/31's workflow engine check classes are `FileName` (basename), `FileMimeType`, `FileSize`, `FileSystemTags`, and `UserGroupMembership`. There is no `FilePath` and no `UserId` check class. Per-(directory, user) rules are not expressible via FAC. Mount-level ACL via `occ files_external:applicable` is the supported primitive and maps cleanly onto the model.
+
+**Manifest**: `kubernetes_config_map_v1.nextcloud_external_storage_manifest` in `stacks/nextcloud/external_storage.tf`. Mount entries reference NC usernames (`admin`, `anca`, `emo` — not display names; admin is Viktor). JSON shape:
+```json
+{
+  "rootMounts": [
+    { "mountPoint": "/PVE NFS Pool",     "dataDir": "/mnt/pve-nfs",     "applicableGroup": "admin", "enableSharing": true },
+    { "mountPoint": "/PVE NFS-SSD Pool", "dataDir": "/mnt/pve-nfs-ssd", "applicableGroup": "admin", "enableSharing": true }
+  ],
+  "archiveMounts": [
+    { "mountPoint": "/anca-elements", "dataDir": "/mnt/pve-nfs/anca-elements", "applicableUsers": ["anca", "admin"], "applicableGroups": [], "enableSharing": false }
+  ]
+}
+```
+A one-shot K8s bootstrap Job applies the manifest idempotently on every `tg apply` via `occ files_external:*`, `occ files_external:applicable`, and `occ files_external:option`. `enableSharing: true` lets admin re-share a subfolder of the mount with another NC user/group/public link; default is `false` (NC's local-backend default).
+
+**Adding a new archive**: drop the directory under `/srv/nfs/<name>/` on PVE, append an `archiveMounts` entry to the manifest, then `scripts/tg apply` the nextcloud stack. See `docs/runbooks/nextcloud-add-archive.md` for the full step-by-step.
+
+**Trade-off**: a compromised NC admin account has destructive reach over the cluster NFS roots (admin sees the root browser mounts). Accepted — Viktor's account is the single high-value target either way. No lateral movement to databases or block PVCs via this path (those are not NFS).
+
+**Backup**: Synology retains a frozen copy of each archive (3-2-1 coverage); the existing `offsite-sync-backup` pipeline provides nightly delta sync from `/srv/nfs/<archive>` → Synology `nfs/`.
+
 ## Related
 
 - **Runbooks**:
   - `docs/runbooks/restore-postgresql.md`
   - `docs/runbooks/restore-mysql.md`
   - `docs/runbooks/recover-nfs-mount.md`
+  - `docs/runbooks/nextcloud-add-archive.md`
 - **Architecture**: `docs/architecture/backup-dr.md` (backup strategy using LVM snapshots and Proxmox host scripts)
 - **Reference**: `.claude/reference/service-catalog.md` (which services use NFS vs proxmox-lvm)
diff --git a/docs/runbooks/nextcloud-add-archive.md b/docs/runbooks/nextcloud-add-archive.md
new file mode 100644
index 00000000..3dac363c
--- /dev/null
+++ b/docs/runbooks/nextcloud-add-archive.md
@@ -0,0 +1,57 @@
+# Runbook: Add a new archive to Nextcloud / PVE NFS
+
+Use this runbook when you need to surface a new directory under `/srv/nfs/` or `/srv/nfs-ssd/` to specific Nextcloud users as a dedicated External mount. Each archive gets its own NC mount; only the listed `applicableUsers` can see and access it.
+
+## Steps
+
+1. **Create the directory on PVE.**
+
+   ```bash
+   ssh root@192.168.1.127
+   mkdir -p /srv/nfs/<archive-name>
+   # Use /srv/nfs-ssd/<archive-name> for the SSD pool instead.
+   ```
+
+2. **Populate the directory.**
+
+   Rsync from a remote source, copy from another NFS path, or let the granted user upload via the NC web UI after step 5. Example rsync:
+
+   ```bash
+   rsync -avP --info=progress2 user@source:/path/ /srv/nfs/<archive-name>/
+   ```
+
+3. **Add a manifest entry.**
+
+   Edit `infra/stacks/nextcloud/external_storage.tf`. In the `kubernetes_config_map_v1.nextcloud_external_storage_manifest` resource, append a new entry to `archiveMounts`:
+
+   ```json
+   { "mountPoint": "/<archive-name>", "dataDir": "/mnt/pve-nfs/<archive-name>", "applicableUsers": ["<owner1>", "admin"], "applicableGroups": [], "enableSharing": false }
+   ```
+
+   Use `/mnt/pve-nfs-ssd/<archive-name>` for the SSD pool. NC usernames are `admin`, `anca`, `emo` — not display names (`admin` is Viktor). `admin` is included so the owner of the homelab can always assist with the archive. Set `enableSharing: true` only if you want recipients to re-share subfolders.
+
+4. **Plan and apply.**
+
+   ```bash
+   cd infra/stacks/nextcloud
+   scripts/tg plan
+   scripts/tg apply
+   ```
+
+   The bootstrap Job re-runs and applies the new mount plus `applicable_users` idempotently via `occ files_external:*` and `occ files_external:applicable`. No manual `occ` invocation needed.
+
+5. **Verify.**
+
+   Log in as a granted user — `/<archive-name>` must appear in their NC sidebar; read, upload, and delete must all work. Log in as a non-granted user and confirm the mount is not visible at all.
+
+## Backout
+
+Remove the entry from `archiveMounts` in the manifest ConfigMap, then `scripts/tg apply`. The bootstrap Job re-runs and removes the mount. The root mounts (`PVE NFS Pool`, `PVE NFS-SSD Pool`, visible to group `admin` only) are unaffected throughout.
+
+After the mount is gone there is no NC trash to clean. The directory on PVE (`/srv/nfs/<archive-name>`) can be `rmdir`'d once you have confirmed the data is safe elsewhere.
+
+## Related
+
+- Architecture: `docs/architecture/storage.md` — "Nextcloud as PVE-NFS browser" section
+- Original design/plan: `infra/docs/plans/2026-05-23-anca-elements-{design,plan}.md` <!-- TODO: confirm path once orchestrator files the plan docs -->
+- Manifest source: `infra/stacks/nextcloud/external_storage.tf` (`kubernetes_config_map_v1.nextcloud_external_storage_manifest`)
diff --git a/scripts/anca-elements-sync.sh b/scripts/anca-elements-sync.sh
new file mode 100755
index 00000000..e3fa14f7
--- /dev/null
+++ b/scripts/anca-elements-sync.sh
@@ -0,0 +1,112 @@
+#!/usr/bin/env bash
+# anca-elements-sync.sh — copy Anca's WD-Elements backup from Synology to PVE NFS
+#
+# Usage:
+#   /usr/local/bin/anca-elements-sync.sh
+#
+# Idempotent: re-running after a successful sync is a no-op (only the dry-run
+# verification runs, which reports "sync verified clean" immediately).
+#
+# Resumable: if fpsync was interrupted, resume with:
+#   fpsync -r /var/tmp/fpsync \
+#     -n 4 -s 4G \
+#     -o "-lptgoD -H --no-perms --no-owner --no-group --exclude=@eaDir/ --exclude=*@synoeastream --exclude=.DS_Store --exclude=Thumbs.db" \
+#     /mnt/synology-backup/Anca/Elements/ /srv/nfs/anca-elements/
+#
+# NOTE: fpsync -o = rsync options override (what we want)
+#       fpsync -O = fpart partition options override (NOT rsync)
+# NOTE: Do NOT use -a or -r in fpsync rsync options — fpsync handles
+#       recursion via fpart; -r causes fpsync to warn and skip the slab.
+#
+# Log: /var/log/anca-elements-sync.log
+
+set -euo pipefail
+
+LOG=/var/log/anca-elements-sync.log
+SRC_HOST=192.168.1.13
+SRC_EXPORT=/volume1/Backup
+SRC_SUBPATH=Anca/Elements
+MOUNT_POINT=/mnt/synology-backup
+DEST=/srv/nfs/anca-elements
+
+log() {
+    echo "[$(date -u '+%Y-%m-%dT%H:%M:%SZ')] $*" | tee -a "$LOG"
+}
+
+# ── 1. Ensure destination + mount-point directories exist ────────────────────
+log "Step 1: ensuring directories"
+mkdir -p "$DEST" "$MOUNT_POINT"
+
+# ── 2. NFS-mount Synology read-only (skip if already mounted) ───────────────
+MOUNTED_HERE=0
+if mountpoint -q "$MOUNT_POINT"; then
+    log "Step 2: $MOUNT_POINT already mounted — skipping"
+else
+    log "Step 2: mounting ${SRC_HOST}:${SRC_EXPORT} at $MOUNT_POINT (read-only)"
+    mount -t nfs \
+        -o ro,vers=4,nolock,soft,timeo=300,retrans=2 \
+        "${SRC_HOST}:${SRC_EXPORT}" \
+        "$MOUNT_POINT"
+    MOUNTED_HERE=1
+    log "Step 2: mount successful"
+fi
+
+# ── 3. Ensure fpsync (from fpart package) is available ──────────────────────
+log "Step 3: checking for fpsync"
+if ! command -v fpsync >/dev/null 2>&1; then
+    log "Step 3: fpsync not found — installing fpart"
+    apt-get install -y fpart
+    log "Step 3: fpart installed"
+else
+    log "Step 3: fpsync already available"
+fi
+
+# ── 4. Run fpsync (4-way parallel, no compression — source is already-compressed media) ──
+log "Step 4: starting fpsync"
+log "  source : ${MOUNT_POINT}/${SRC_SUBPATH}/"
+log "  dest   : ${DEST}/"
+log "  workers: 4, slab: 4G"
+fpsync \
+    -n 4 \
+    -s 4G \
+    -o "-lptgoD -H --no-perms --no-owner --no-group --exclude=@eaDir/ --exclude=*@synoeastream --exclude=.DS_Store --exclude=Thumbs.db" \
+    "${MOUNT_POINT}/${SRC_SUBPATH}/" \
+    "${DEST}/" \
+    2>&1 | tee -a "$LOG"
+log "Step 4: fpsync completed"
+
+# ── 5. Verification dry-run ──────────────────────────────────────────────────
+log "Step 5: running dry-run verification rsync"
+VERIFY_OUT=$(rsync \
+    -rlptgoD -H --no-perms --no-owner --no-group \
+    --exclude='@eaDir/' --exclude='*@synoeastream' \
+    --exclude='.DS_Store' --exclude='Thumbs.db' \
+    -n --delete \
+    --info=progress2 \
+    --out-format='%o %f' \
+    "${MOUNT_POINT}/${SRC_SUBPATH}/" \
+    "${DEST}/" \
+    2>&1 || true)
+
+# Count lines that represent actual file changes (send / del. operations)
+CHANGE_COUNT=$(echo "$VERIFY_OUT" | grep -cE '^(send|del\.)' || true)
+
+if [ "$CHANGE_COUNT" -eq 0 ]; then
+    log "Step 5: sync verified clean — no pending changes"
+else
+    log "Step 5: WARNING — verification found ${CHANGE_COUNT} pending change(s). First 50 lines:"
+    # Use printf to avoid SIGPIPE from head closing the pipe early (set -o pipefail)
+    { echo "$VERIFY_OUT" | head -50; } >> "$LOG" 2>&1 || true
+fi
+
+# ── 6. Unmount (only if we mounted it) ──────────────────────────────────────
+if [ "$MOUNTED_HERE" -eq 1 ]; then
+    log "Step 6: unmounting $MOUNT_POINT"
+    umount "$MOUNT_POINT"
+    rmdir "$MOUNT_POINT"
+    log "Step 6: unmounted"
+else
+    log "Step 6: mount was pre-existing — leaving in place"
+fi
+
+log "Done. Final size: $(du -sh "${DEST}" | cut -f1)"