Users with removable/unmounted datastores (e.g., external HDDs for
offline backup) experienced excessive PBS log entries because Pulse
was querying all datastores including unavailable ones.
Added `excludeDatastores` field to PBS node configuration that accepts
patterns to exclude specific datastores from monitoring:
- Exact names: "exthdd1500gb"
- Prefix patterns: "ext*"
- Suffix patterns: "*hdd"
- Contains patterns: "*removable*"
Pattern matching is case-insensitive.
Fixes#1105
Add 13 test cases for convertPBSSnapshots covering:
- Empty/nil input handling
- Basic snapshot field mapping
- Files as string array
- Files as object array with filename field
- Invalid file objects ignored gracefully
- Verification status as string ("ok" vs other)
- Verification status as object with state field
- Verification object without state field
- Multiple snapshots with unique IDs
- Empty namespace handling in ID generation
- Container (ct) backup type
Coverage: convertPBSSnapshots 0% -> 100%