Multiple translation bugs in Word/Excel/PPTX that caused chart elements
to be left untranslated or charts to render as empty series.
Backend
-------
* providers (deepseek/openai/minimax): tighten system prompt so the LLM
actually translates chart titles/axis labels/legend/category labels,
month abbreviations, and clarifies what counts as a 'real' proper noun
(people/place/company/product names) vs. technical labels. Old rule
'keep proper nouns unchanged' was being read too broadly by the model
and caused chart text to be skipped.
* excel_translator.py:
- Sheet reference rewrite: when a sheet is renamed, the chart XML's
c:f refs (e.g. 'Sales 2024'!$D$2:$D$61) are now rewritten to the
new name with proper apostrophe escaping (Chiffre d'affaires ->
'Chiffre d''affaires') and auto-quoting when the new name contains
spaces or special chars. Without this, the chart points at a sheet
that no longer exists and renders 0/empty series.
- Sheet name offset bug: sheet_name_offset was computed after chart
text was appended to text_elements, causing sheet names to receive
chart text translations. Now captured BEFORE sheet names are added.
* New tests:
- test_excel_chart_sheet_refs.py (10 unit tests, synthetic inputs)
- test_chart_translation_prompt.py (3 contract tests on the prompt)
Frontend
--------
* DashboardSidebar / translate/page: hide the Memento promo section
for paying users (tier != 'free').
* constants.ts: temporarily comment out the 'CLES API' nav item.
Update constants.test.ts to match the new state.
All fixes are generic - no file-specific hardcoding, edge cases covered
(empty mapping, missing bang, apostrophe escaping, partial renames,
multi-series).
