Fix set_metadata_purge_interval to use correct REST API parameters

The previous implementation used metadataPurgeInterval parameter which
does not work for per-bucket configuration. The REST API requires
specific parameters to enable and configure per-bucket auto-compaction.

Changes:
- Use autoCompactionDefined=true to enable per-bucket override
- Use purgeInterval instead of metadataPurgeInterval
- Add parallelDBAndViewCompaction=false (required by API)
- Add verification call to confirm configuration was applied

This aligns the Rust function with the corrected bash script in
configure-server.sh to ensure consistent bucket configuration.

Without these parameters, the bucket retains cluster-wide defaults
and per-bucket purge interval is not applied.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: pimpin

examples/utils/cbs_admin.rs

@@ -227,7 +227,14 @@ pub fn set_metadata_purge_interval(days: f64) {
     }
 
     let url = format!("{CBS_URL}/pools/default/buckets/{CBS_BUCKET}");
-    let params = [("metadataPurgeInterval", days.to_string())];
+
+    // IMPORTANT: Must set autoCompactionDefined=true to enable per-bucket override
+    // parallelDBAndViewCompaction is also required by the API
+    let params = [
+        ("autoCompactionDefined", "true"),
+        ("purgeInterval", &days.to_string()),
+        ("parallelDBAndViewCompaction", "false"),
+    ];
 
     let response = reqwest::blocking::Client::new()
         .post(&url)