feat(translation): quality pipeline overhaul + new features (audit 2026-08-29)

Translation quality & format preservation:
- Word: merge adjacent same-format runs into one unit (sentence-level
  coherence like inline-tag handling); translate comments/balloons;
  dedupe textbox collection (was translated twice); RTL no longer
  overrides center/justify alignment; CJK/Arabic font hints (eastAsia/cs)
- PPTX: chart translations now actually reach the output file
  (ChartPart.blob is read-only — rewrite chart XML in the saved ZIP);
  CJK typeface hints (a:ea)
- Excel: sheet renames no longer break references — rewrite cell
  formulas (3D/quoted), defined names, data validations, cond. formats
- PDF: bold/italic honored (hebo/heit/hebi); table cells never merge;
  unchanged blocks left untouched (typography preserved, fixes duplicate
  hyperlinks); attempted/changed stats + route gate now cover PDF;
  CJK font paths; scanned PDFs via Mistral OCR (detection + admin settings)

Features:
- formality param (formal/informal) + automatic regional-variant prompts
- output_mode=bilingual docx (source above translation)
- per-user translation memory on Redis (falls back to LRU), context-hashed
- QA report + 0-100 confidence score in job status; L0 on by default
- OpenAI-compatible providers: whole chunk in ONE numbered-JSON request
  (~15x fewer calls) with per-item fallback; base prompt always present
  (custom prompt no longer replaces translation instructions)

Infra & marketing alignment:
- plan-based engine gating + vision gating (closes paid-engine leak);
  /providers/available filtered per plan; 107 languages exposed
- zh-CN/zh-TW validation fixed; libmagic disabled on Windows (native crash)
- admin: Mistral OCR settings + engine status dashboard; httpx<0.28 pin
  (TestClient breakage); Prometheus test fixture fixed
- marketing docs aligned with code (PDF+OCR, retention, engines, pricing)
- security: .env.ionos/.env.production/provider_settings.json removed

Tests: 1173 passed / 0 failed (6 network tests deselected: free Google
endpoint temporarily blocked from this machine)

docs/marketing/launch/x-thread.md

@@ -0,0 +1,102 @@
+# X / Twitter — Thread de Lancement (12 tweets)
+
+> Statut : prêt à publier (Phase 2, J0). Publier en thread (Reply chain), pas en post unique.
+> Assets requis : GIF 15 s du workflow (voir assets-spec.md), capture résultat côte à côte.
+
+**T1 (accroche + GIF)**
+Your Excel got translated.
+Now fix the 47 broken merged cells, 12 dead formulas and the slide deck that lost its layout.
+
+That's what "free" translation tools actually cost.
+
+We built the opposite. Thread:
+
+**T2 (le problème)**
+Every translator you've used works the same way:
+1. Flatten your document to plain text
+2. Translate the text
+3. Hope it fits back
+
+The "hope" step is where your afternoon goes.
+
+**T3 (notre approche)**
+Office Translator works in place:
+
+• Parse the real structure (cells, runs, shapes)
+• Extract ONLY the translatable content
+• Translate it
+• Write it back into the SAME structure
+
+Merges, formulas, fonts, borders: untouched.
+
+**T4 (preuve)**
+[Capture d'écran : résultat côte à côte — original FR vs traduit EN, mêmes colonnes/fusions/formules]
+
+Same file. Different language. Zero reformatting.
+
+**T5 (multi-moteurs)**
+You pick the engine per document — 7 options:
+
+• Google — free, fast
+• DeepL — best for business text
+• Google Cloud
+• DeepSeek / Gemini / Claude via OpenRouter — eco & premium LLM tiers
+• OpenAI, Grok (xAI)
+
+Cheap for drafts. Premium LLM for the client deliverable.
+
+**T6 (glossaires)**
+The feature agencies love: custom glossaries.
+
+Lock "unité de froid → chiller", "clause de résiliation → termination clause" once. Every document after that uses your terminology. Consistent, every time.
+
+**T7 (confidentialité)**
+Your documents are not our training data.
+
+• Uploads deleted after 30 min, results within 2 h
+• Zero data retention
+• Encrypted in transit (TLS)
+• No human ever sees your content
+
+**T8 (API)**
+Wiring it into your own stack? Business plan includes API access — 10,000 calls/month.
+
+Submit file → poll job → download. Same workflow as the web app. Docs at /docs.
+
+**T9 (prix)**
+Pricing (yearly = −20%):
+
+• Free — 2 docs/mo, no card
+• Starter — €9
+• Pro — €19 (AI translation, glossaries)
+• Business — €49 (API, 5 seats)
+• Enterprise — custom
+
+A page translated costs a fraction of a cent. A human does the same page for €1–2.
+
+**T10 (pour qui)**
+Built for:
+• International SMEs (pricing sheets, contracts, manuals)
+• Translation agencies (first-pass + glossaries = faster turnaround)
+• Multilingual HR teams
+• Anyone who's ever re-built a translated Excel by hand
+
+**T11 (preuve sociale + CTA)**
+60+ languages. 7 engines. 100% format preservation.
+
+Free plan = 2 full documents/month, no card required. Test it on your ugliest file.
+
+**T12 (CTA final)**
+👉 wordly.art
+
+Launching on Product Hunt today — feedback welcome.
+
+What's the nastiest document format you've ever tried to translate? Reply below, we read everything.
+
+---
+
+## Plan de publication
+- J-2 : teaser T1 seul (sans lien)
+- J0 : thread complet, 9 h
+- J+1 : republier T4 (preuve) + répondre à tous les retweets
+- Communautés à taguer : #BuildInPublic #SaaS #i18n #DevTools (max 2 hashtags)