Revert "Add documents to stock lots"

This reverts commit 2bec934732.

db/migrations/0021_stock_lot_documents.sql

@@ -1,18 +0,0 @@
-BEGIN;
-
-CREATE TABLE stock_lot_document (
-  id BIGSERIAL PRIMARY KEY,
-  stock_lot_id BIGINT NOT NULL REFERENCES stock_lot(id) ON DELETE CASCADE,
-  original_filename TEXT NOT NULL,
-  stored_filename TEXT NOT NULL,
-  mime_type TEXT NOT NULL,
-  size_bytes BIGINT NOT NULL,
-  comment TEXT,
-  uploaded_by TEXT NOT NULL,
-  uploaded_at TIMESTAMP NOT NULL DEFAULT NOW(),
-  CONSTRAINT chk_stock_lot_document_size CHECK (size_bytes > 0 AND size_bytes <= 52428800)
-);
-
-CREATE INDEX idx_stock_lot_document_lot ON stock_lot_document(stock_lot_id, id);
-
-COMMIT;