## Problem
E-conomic API returns HTTP 400 when text-line descriptions contain
certain characters. The most common case is `/` in the order reference
field, which causes the entire draft-invoice export to fail.
## Root cause
When `order.reference` (or notes, reg_*, po) contains `/`, e-conomic's
text-line validation rejects the entire draft with HTTP 400. Same for
control characters and very long strings.
## Fix
Adds `economic_export_sanitizer` class that sanitizes all user-input
fields flowing into e-conomic:
- `/` → `-` (the reported 400 trigger)
- Control chars stripped (\x00-\x1F except \t and \n)
- Tab and newline → single space
- Whitespace normalized and trimmed
- Lengths capped (text 250, product 50, description 500) with `...`
suffix
- Multibyte safe (æ, ø, å, emoji, Chinese)
## Applied to
In `economic_invoice_draft.php`:
- `order.po`
- `order.reference` (PRIMARY FIX for the reported issue)
- `order.notes`
- `order.reg_1/2/3`
- `order_item.reference`
- `order_item.notes`
- `product.description`
- `product.productNumber`
- `department_name`
## Test coverage
- 31 unit tests with 45 assertions
- All edge cases (null, empty, control chars, multibyte, very long,
HTML, control chars in every position)
- Lint and test suite both pass
## Linear
Refs: TRU-189, TRU-190, TRU-191, TRU-192, TRU-193, TRU-194, TRU-196
Co-authored-by: OpenClaw <openclaw@copenhagentruckwash.io>
