Add SAS Service for Ctrl+Alt+Del support

- New guruconnect-sas-service binary (runs as SYSTEM)
- Named pipe IPC for agent-to-service communication
- Multi-tier SAS approach: service > sas.dll > fallback
- Service auto-install/uninstall helpers in startup.rs

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

agent/Cargo.toml

@@ -75,6 +75,8 @@ windows = { version = "0.58", features = [
     "Win32_System_Console",
     "Win32_Security",
     "Win32_Storage_FileSystem",
+    "Win32_System_Pipes",
+    "Win32_System_SystemServices",
 ]}
 
 # Windows service support
@@ -84,6 +86,14 @@ windows-service = "0.7"
 prost-build = "0.13"
 winres = "0.1"
 
+[[bin]]
+name = "guruconnect-agent"
+path = "src/main.rs"
+
+[[bin]]
+name = "guruconnect-sas-service"
+path = "src/bin/sas_service.rs"
+
 [profile.release]
 lto = true
 codegen-units = 1