feat: agent Rust Phase 2 — visual mode (template matching serveur)

- visual.rs : resolve via POST /replay/resolve_target
- executor.rs : resolve avant chaque clic si visual_mode=true
- Fallback blind si matching échoue
- Binaire toujours 1.8 MB (pas de nouvelle dépendance)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

agent_rust/src/main.rs

@@ -14,6 +14,7 @@ mod executor;
 mod network;
 mod replay;
 mod server;
+mod visual;
 
 use config::Config;
 use reqwest::blocking::Client;