Refactor garbage collection to prevent premature pruning and panic vu…

lore-storage/src/maintenance.rs

@@ -122,7 +122,8 @@ pub async fn gc(
     max_capacity: usize,
     sync_data: bool,
     sink: Option<GcEventSinkRef>,
-) {
+    grace_period: Option<Duration>,
+) -> Result<(), crate::gc::GcError> {
     let mut at = store.clone().compact_resume_at().await;
 
     if max_size > 0 {
@@ -146,17 +147,24 @@ pub async fn gc(
                 }
                 Err(err) => {
                     lore_base::lore_warn!("Store compactor failed: {err}");
-                    break;
+                    return Err(crate::gc::GcError::CompactionFailed(err.to_string()));
                 }
             }
         }
         lore_base::lore_debug!("Store compactor done");
     }
 
     if max_capacity > 0 {
-        let _ = store.evict(max_capacity, sync_data, sink).await;
+        // Enforce staging leases and grace period timestamp checking for atomic rollbacks
+        let _transaction = crate::gc_lease::acquire_exclusive_sweep()
+            .map_err(|e| crate::gc::GcError::LeaseDenied(e.to_string()))?;
+
+        store.evict_with_grace(max_capacity, sync_data, sink, grace_period).await
+            .map_err(|e| crate::gc::GcError::EvictionFailed(e.to_string()))?;
         lore_base::lore_debug!("Store evictor done");
     }
+
+    Ok(())
 }
 
 /// Per-store running totals, collected purely as a byproduct of LOADING data from

lore/src/repository.rs

@@ -707,7 +707,12 @@ async fn flush_local(
 #[repr(C)]
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize, LoreArgs)]
 #[handler(gc_local)]
-pub struct LoreRepositoryGcArgs {}
+pub struct LoreRepositoryGcArgs {
+    /// Grace period (in seconds) to spare newly created fragments from premature pruning
+    pub grace_period_sec: u64,
+    /// Minimum size threshold (in bytes) to trigger pruning
+    pub prune_threshold: u64,
+}
 
 /// Runs garbage collection on the local repository store to reclaim space from unreferenced data.
 ///