refactor: optimize middleware with pure ASGI implementation and enhance security measures

- Replace BaseHTTPMiddleware with pure ASGI implementation in plugin middleware for better streaming response handling
- Add trusted proxy count configuration for client IP extraction in reverse proxy environments
- Implement audit log cleanup scheduler with configurable retention period
- Replace plaintext token logging with SHA256 hash fingerprints for security
- Fix database session lifecycle management in middleware
- Improve request tracing and error logging throughout the system
- Add comprehensive tests for pipeline architecture

frontend/src/features/usage/components/RequestDetailDrawer.vue

@@ -25,7 +25,7 @@
                 </h3>
                 <div class="flex items-center gap-1 text-sm font-mono text-muted-foreground bg-muted px-2 py-0.5 rounded">
                   <span>{{ detail?.model || '-' }}</span>
-                  <template v-if="detail?.target_model">
+                  <template v-if="detail?.target_model && detail.target_model !== detail.model">
                     <svg
                       xmlns="http://www.w3.org/2000/svg"
                       viewBox="0 0 20 20"