Invoice import: strip all AI/OCR dependencies, use regex-only extraction
with pdfplumber text+tables as input. Add tax extraction, amount-line
item scanning, and subset-sum reconciliation. Generic item names
("Eingangsrechnung") replace raw invoice text, originals preserved in
description field.
Lock: rewrite to Redis-only (single key per review item) instead of
file-lock + signature-based keys. Fixes locks breaking after every save
because doc.get_signature() changes with modified timestamp. Also fixes
owner cache expiring independently of heartbeat, and JS re-acquisition
guard (__review_lock_attempted) blocking retries forever.
Settings: remove OCR/AI/Ollama fields, add import_item_name.
Approvals: handle case where no approvers configured (approval not required).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
