fix: Inbox/Uploads unter gemeinsamem Bind-Mount (EXDEV bei Path.replace)

Beim E2E-Smoke-Test schlug der Import mit 'Invalid cross-device link'
fehl: rename() funktioniert nicht ueber zwei getrennte Bind-Mounts.
Inbox und Uploads liegen jetzt unter einem einzigen /data-Mount.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

create_pod_finance.sh

@@ -31,8 +31,15 @@ GRAFANA_CONTAINER_PORT='3000'
 BIND_DIR="$HOME/.local/share/$POD_NAME"
 POSTGRES_DATA_DIR="$BIND_DIR/postgres-data"
 GRAFANA_DATA_DIR="$BIND_DIR/grafana-data"
-INBOX_DIR="$BIND_DIR/inbox"
-UPLOADS_DIR="$BIND_DIR/uploads"
+# inbox and uploads must live under one shared bind mount: process_pdf()
+# moves a file from inbox to uploads via Path.replace() (os.replace/rename),
+# which fails with EXDEV ("Invalid cross-device link") across two separate
+# bind mounts even when both point at the same underlying host filesystem
+# (Linux permits a filesystem to be mounted at multiple points, but rename()
+# does not work across different mount points - see `man 2 rename`).
+DATA_DIR="$BIND_DIR/data"
+INBOX_DIR="$DATA_DIR/inbox"
+UPLOADS_DIR="$DATA_DIR/uploads"
 USER_SYSTEMD_DIR="$HOME/.config/systemd/user"
 
 FINANCE_DIR="$HOME/bin/finance"
@@ -142,8 +149,7 @@ podman run -d --name "$API_CTR_NAME" --pod "$POD_NAME" \
   -e FB_GUI_PASSWORD_HASH \
   -e FB_INBOX_DIR=/data/inbox \
   -e FB_UPLOADS_DIR=/data/uploads \
-  -v "$INBOX_DIR:/data/inbox:Z" \
-  -v "$UPLOADS_DIR:/data/uploads:Z" \
+  -v "$DATA_DIR:/data:Z" \
   "$API_IMAGE"
 echo "Container '$API_CTR_NAME' started (rc=$?)"