Fix filesystem metric parsing for correct mount point names

- Fix extract_filesystem_metric() to handle multi-underscore metric names correctly
- Parse known metric suffixes (usage_percent, mount_point, available_gb, etc.)
- Prevent incorrect parsing like boot_mount_point -> fs_name='boot_mount', metric_type='point'
- Should now correctly show /boot and / instead of /boot/mount and /root/mount

Cargo.lock

@@ -279,7 +279,7 @@ checksum = "a1d728cc89cf3aee9ff92b05e62b19ee65a02b5702cff7d5a377e32c6ae29d8d"
 
 [[package]]
 name = "cm-dashboard"
-version = "0.1.104"
+version = "0.1.105"
 dependencies = [
  "anyhow",
  "chrono",
@@ -301,7 +301,7 @@ dependencies = [
 
 [[package]]
 name = "cm-dashboard-agent"
-version = "0.1.104"
+version = "0.1.105"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -324,7 +324,7 @@ dependencies = [
 
 [[package]]
 name = "cm-dashboard-shared"
-version = "0.1.104"
+version = "0.1.105"
 dependencies = [
  "chrono",
  "serde",