Update README with current features and screenshots

- Cross-platform support (Windows/Linux) with Windows Updates and Winget
- Added dependency confirmation workflow and refresh token authentication
- New screenshots: History, Live Operations, Windows Agent Details
- Local CLI features with terminal output and cache system
- Updated known limitations - Proxmox integration is broken
- Organized docs to docs/ folder and updated .gitignore
- Probably introduced a dozen bugs with Windows agents - stay tuned

aggregator-agent/internal/config/config.go

@@ -13,7 +13,8 @@ import (
 type Config struct {
 	ServerURL       string    `json:"server_url"`
 	AgentID         uuid.UUID `json:"agent_id"`
-	Token           string    `json:"token"`
+	Token           string    `json:"token"`            // Short-lived access token (24h)
+	RefreshToken    string    `json:"refresh_token"`    // Long-lived refresh token (90d)
 	CheckInInterval int       `json:"check_in_interval"`
 }