feat: add Vision LLM integration (CLIP + Qwen3-VL cascade)

- Add Qwen3-VL dynamic management (start/stop/status CLI)
- Add CLIP + Qwen3-VL cascade detection strategy
- Add Vision CLI commands (vision start/stop/status, detect)
- Add cascade_vision processor module
- Add clip processor module
- Add qwen_vl_manager module

Changes:
- scripts/start_qwen3vl.sh, stop_qwen3vl.sh: Qwen3-VL management scripts
- src/core/vision/: Qwen3-VL manager module
- src/core/processor/cascade_vision.rs: CLIP + Qwen3-VL cascade logic
- src/core/processor/clip.rs: CLIP classification and detection
- src/api/clip_api.rs: CLIP API endpoints
- src/cli/vision.rs: Vision CLI implementation
- src/cli/args.rs: Add Vision and Detect commands
- src/main.rs: Integrate Vision CLI
- src/core/mod.rs: Add vision module
- src/core/processor/mod.rs: Add cascade_vision module

src/api/llm_search.rs

@@ -1,10 +1,4 @@
-use axum::{
-    extract::State,
-    http::StatusCode,
-    response::Json,
-    routing::post,
-    Router,
-};
+use axum::{extract::State, http::StatusCode, response::Json, routing::post, Router};
 use serde::Deserialize;
 use tracing::warn;