Add organization/site/tags support for machine grouping

- Added organization, site, tags columns to connect_machines table
- Agent now sends org/site/tags from embedded config in AgentStatus
- Server stores org/site/tags metadata in database
- Enables grouping machines by client/site/tag in dashboard

proto/guruconnect.proto

@@ -277,6 +277,9 @@ message AgentStatus {
     int32 display_count = 5;
     bool is_streaming = 6;
     string agent_version = 7;           // Agent version (e.g., "0.1.0-abc123")
+    string organization = 8;            // Company/organization name
+    string site = 9;                    // Site/location name
+    repeated string tags = 10;          // Tags for categorization
 }
 
 // Server commands agent to uninstall itself