Show app version in admin UI and /version endpoint

Embed APP_VERSION build arg in Docker image (default: dev).
build_push.sh passes the git tag as build arg. Proxy exposes
GET /version, admin UI shows it as read-only field in settings.

backend/admin.py

@@ -131,7 +131,10 @@ async def get_proxy_info(_ = Depends(require_admin_auth)):
     host = os.getenv("PROXY_HOST", "0.0.0.0")
     port = os.getenv("PROXY_PORT", "8000")
     display_host = "localhost" if host in ("0.0.0.0", "::") else host
-    return {"endpoint": f"http://{display_host}:{port}"}
+    return {
+        "endpoint": f"http://{display_host}:{port}",
+        "version": os.getenv("APP_VERSION", "dev"),
+    }
 
 @app.get("/api/settings", response_model=schemas.Settings)
 async def read_settings(db: Session = Depends(get_db), _ = Depends(require_admin_auth)):

backend/main.py

@@ -149,6 +149,10 @@ async def list_models(db: Session = Depends(get_db)):
     response = await proxy_request(f"{ollama_url}/api/tags", method="GET")
     return JSONResponse(content=response.json(), status_code=response.status_code)
 
+@app.get("/version")
+async def version():
+    return {"version": os.getenv("APP_VERSION", "dev")}
+
 @app.get("/api/ps")
 async def running_models(db: Session = Depends(get_db)):
     ollama_url = crud.get_setting(db, "ollama_url", os.getenv("OLLAMA_URL", "http://localhost:11434"))