feat(orgs): Pipeline-Sprache als Org-Setting im Verwaltungsportal

- OrgCreate / OrgUpdate / OrgResponse um output_language (de | en).
- routers/organizations.py persistiert die Sprache nach create/update
  via shared.services.org_settings.set_org_setting.
- _enrich_org liest output_language aus organization_settings (Default de).
- Frontend: Dropdown im Modal Neue Organisation und im Org-Edit-Formular,
  Auto-Befuellung aus org.output_language. Cache-Buster auf app.js gebumpt.

Phase 7 von 8 (eng_demo / Org-Sprache).

src/models.py

@@ -25,11 +25,13 @@ class TokenResponse(BaseModel):
 class OrgCreate(BaseModel):
     name: str = Field(min_length=1, max_length=200)
     slug: str = Field(min_length=1, max_length=100, pattern="^[a-z0-9-]+$")
+    output_language: str = Field(default="de", pattern="^(de|en)$")
 
 
 class OrgUpdate(BaseModel):
     name: Optional[str] = Field(default=None, max_length=200)
     is_active: Optional[bool] = None
+    output_language: Optional[str] = Field(default=None, pattern="^(de|en)$")
 
 
 class OrgResponse(BaseModel):
@@ -43,6 +45,7 @@ class OrgResponse(BaseModel):
     created_at: str
     globe_access: bool = False
     network_access: bool = False
+    output_language: str = "de"
 
 
 class LicenseCreate(BaseModel):