feat: add multilingual glossary support (backend + frontend types)

Backend:
- Add source_language column to glossaries table
- Add translations JSON column to glossary_terms table
- Alembic migration for schema changes
- format_glossary_for_prompt now language-aware: extracts correct
  translation per target language, falls back to EN reference for
  templates with only FR→EN data
- CRUD routes accept/return source_language and translations
- Pydantic schemas updated

Frontend:
- Types updated: GlossaryTerm now has translations: Record<string, string>
- Glossary/GlossaryListItem now have source_language
- Added SUPPORTED_LANGUAGES constant (13 languages)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

schemas/glossary_schemas.py

@@ -17,6 +17,9 @@ class GlossaryTermCreate(BaseModel):
     target: str = Field(
         ..., min_length=1, max_length=500, description="Traduction cible"
     )
+    translations: Optional[dict[str, str]] = Field(
+        None, description="Traductions multilingues: {\"en\": \"coil\", \"de\": \"Spule\", ...}"
+    )
 
     @field_validator("source", "target")
     @classmethod
@@ -30,6 +33,7 @@ class GlossaryTermResponse(BaseModel):
     id: str
     source: str
     target: str
+    translations: dict[str, str] = {}
     created_at: Optional[datetime] = None
 
     model_config = {"from_attributes": True}
@@ -39,6 +43,9 @@ class GlossaryCreate(BaseModel):
     """Schema for creating a glossary."""
 
     name: str = Field(..., min_length=1, max_length=255, description="Nom du glossaire")
+    source_language: str = Field(
+        default="fr", max_length=10, description="Langue source (ISO code)"
+    )
     terms: list[GlossaryTermCreate] = Field(
         default_factory=list, description="Liste des termes"
     )
@@ -53,6 +60,7 @@ class GlossaryUpdate(BaseModel):
     """Schema for updating a glossary (all fields optional)."""
 
     name: Optional[str] = Field(None, min_length=1, max_length=255)
+    source_language: Optional[str] = Field(None, max_length=10)
     terms: Optional[list[GlossaryTermCreate]] = Field(None)
 
     @field_validator("name")
@@ -66,6 +74,7 @@ class GlossaryResponse(BaseModel):
 
     id: str
     name: str
+    source_language: str = "fr"
     terms: list[GlossaryTermResponse] = []
     created_at: Optional[datetime] = None
     updated_at: Optional[datetime] = None
@@ -78,6 +87,7 @@ class GlossaryListItem(BaseModel):
 
     id: str
     name: str
+    source_language: str = "fr"
     terms_count: int = Field(
         default=0, description="Nombre de termes dans le glossaire"
     )