fix(relecture): un travail vide ou oublie restait affiche et impossible a retirer

Un travail echoue ou expire cote serveur restait dans « Traductions
recentes » : sa page de relecture n'affichait rien (0 segments) avec une
erreur brute non traduite, et aucune suppression n'existait.

- serveur : nouvelle route DELETE /api/v1/translations/{job_id} —
  retire le travail de la memoire et de Redis, supprime ses segments de
  relecture ; idempotente (200 meme si le serveur avait deja oublie le
  travail) ; refuse les travaux en cours (annuler d'abord) ; proprietaire
  seul (404 pour le travail d'autrui, sans reveler son existence)
- interface : bouton corbeille sur chaque ligne des traductions recentes
  (deux clics pour confirmer) qui nettoie la liste locale ET le serveur ;
  l'historique serveur ne liste plus les travaux non termines
- page de relecture : message d'erreur traduit (fini le message brut) et
  etat « rien a relire » explicite avec explication
- libelles ajoutes dans les 13 langues de l'interface
- 5 tests backend nouveaux (tests/test_delete_translation_history.py)

routes/translate_routes.py

@@ -71,7 +71,7 @@ from utils.file_handler import FileHandler
 from middleware.metrics import record_translation, record_file_size
 from services.progress_tracker import ProgressTracker
 from services.storage_tracker import storage_tracker
-from core.redis import set_job_status_async, get_job_status_async
+from core.redis import set_job_status_async, get_job_status_async, delete_job_status_async
 from services.glossary_service import get_glossary_terms, validate_glossary_access, build_full_prompt
 from services.prompt_service import get_prompt_content, validate_prompt_access
 from utils.exceptions import GlossaryNotFoundError, PromptNotFoundError
@@ -2257,6 +2257,92 @@ async def cancel_translation(
     return {"data": {"id": job_id, "status": "cancelled"}, "meta": {}}
 
 
+@router_v1.delete(
+    "/translations/{job_id}",
+    responses={
+        200: {"description": "Job removed from the user's history (idempotent)"},
+        401: {"description": "Authentication required"},
+        404: {"description": "Job belongs to another user"},
+        409: {"description": "Job is queued or processing — cancel it first"},
+    },
+)
+async def delete_translation(
+    job_id: str,
+    current_user: Optional[Any] = Depends(get_authenticated_user),
+):
+    """
+    Remove a translation job from the user's history.
+
+    Deletes the in-memory job record, its Redis status key and its stored
+    review segments. Idempotent: a job the server has already forgotten
+    (retention expiry, restart) still returns 200 so the client can clean
+    its own list. Only the owner may delete — the share token does not
+    grant deletion rights. Files on disk are left to the TTL cleanup.
+    """
+    if current_user is None:
+        return JSONResponse(
+            status_code=401,
+            content={"error": "AUTH_REQUIRED", "message": "Authentication required."},
+        )
+    user_id = str(getattr(current_user, "id", ""))
+
+    job = _translation_jobs.get(job_id)
+    if not job:
+        job = await get_job_status_async(job_id)
+
+    if job:
+        # Do not reveal whether someone else's job exists: same 404 body.
+        if str(job.get("user_id", "")) != user_id:
+            return JSONResponse(
+                status_code=404,
+                content={
+                    "error": "NOT_FOUND",
+                    "message": "Translation job not found.",
+                    "details": {"job_id": job_id},
+                },
+            )
+        if job.get("status") in ("queued", "processing"):
+            return JSONResponse(
+                status_code=409,
+                content={
+                    "error": "JOB_IN_PROGRESS",
+                    "message": "Cancel the job before deleting it.",
+                    "details": {"job_id": job_id, "status": job.get("status")},
+                },
+            )
+
+    _translation_jobs.pop(job_id, None)
+    await delete_job_status_async(job_id)
+
+    def _delete_segments():
+        from database.connection import get_sync_session
+        from database.models import TranslationSegment
+
+        with get_sync_session() as session:
+            deleted = (
+                session.query(TranslationSegment)
+                .filter(TranslationSegment.job_id == job_id)
+                .delete()
+            )
+            session.commit()
+            return deleted
+
+    segments_deleted = 0
+    try:
+        segments_deleted = await asyncio.to_thread(_delete_segments)
+    except Exception as seg_err:
+        logger.warning(f"Job {job_id}: segment deletion failed: {seg_err}")
+
+    logger.info(
+        f"Job {job_id}: deleted from history by user "
+        f"(segments removed: {segments_deleted})"
+    )
+    return {
+        "data": {"id": job_id, "deleted": True, "segments_removed": segments_deleted},
+        "meta": {},
+    }
+
+
 @router_v1.get("/translate/health")
 async def translate_health():
     """Health check for translation endpoint."""