Complete atomic migration to structured data architecture

Implements clean structured data collection eliminating all string metric
parsing bugs. Collectors now populate AgentData directly with type-safe
field access.

Key improvements:
- Mount points preserved correctly (/ and /boot instead of root/boot)
- Tmpfs discovery added to memory collector
- Temperature data flows as typed f32 fields
- Zero string parsing overhead
- Complete removal of MetricCollectionManager bridge
- Direct ZMQ transmission of structured JSON

All functionality maintained: service tracking, notifications, status
evaluation, and multi-host monitoring.

dashboard/src/ui/widgets/system.rs

@@ -236,7 +236,7 @@ impl SystemWidget {
 
         for pool in &self.storage_pools {
             // Pool header line with type and health
-            let pool_label = if pool.pool_type.starts_with("drive (") {
+            let pool_label = if pool.pool_type == "drive" {
                 // For physical drives, show the drive name with temperature and wear percentage if available
                 // Look for any drive with temp/wear data (physical drives may have drives named after the pool)
                 let drive_info = pool.drives.iter()
@@ -269,7 +269,7 @@ impl SystemWidget {
             lines.push(Line::from(pool_spans));
 
             // Show individual filesystems for physical drives (matching CLAUDE.md format)
-            if pool.pool_type.starts_with("drive") {
+            if pool.pool_type == "drive" {
                 // Show filesystem entries like: ├─ ● /: 55% 250.5GB/456.4GB
                 for (i, filesystem) in pool.filesystems.iter().enumerate() {
                     let is_last = i == pool.filesystems.len() - 1;