fix(postgres): Fix additional clippy warnings in workers module

- Remove unnecessary cast in types/vector.rs:549
- Use div_ceil() instead of manual computation in workers/ipc.rs
- Replace redundant closure with function reference in workers/ipc.rs
- Derive Default for MaintenanceStats in workers/maintenance.rs
- Derive Default for TaskPriority enum in workers/queue.rs
- Use or_default() instead of or_insert_with(Vec::new) in workers/mod.rs

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

crates/ruvector-postgres/src/types/vector.rs

@@ -546,7 +546,7 @@ pub extern "C" fn ruvector_send(fcinfo: pg_sys::FunctionCallInfo) -> pg_sys::Dat
         let bytea_ptr = pg_sys::palloc(bytea_size) as *mut pg_sys::bytea;
 
         // Set size
-        pgrx::varlena::set_varsize_4b(bytea_ptr as *mut pg_sys::varlena, bytea_size as i32);
+        pgrx::varlena::set_varsize_4b(bytea_ptr, bytea_size as i32);
 
         // Copy data
         let bytea_data = pgrx::varlena::vardata_any(bytea_ptr as *const pg_sys::varlena) as *mut u8;

crates/ruvector-postgres/src/workers/ipc.rs

@@ -406,7 +406,7 @@ impl LargePayloadSegment {
             return None;
         }
 
-        let slots_needed = (size + SLOT_SIZE - 1) / SLOT_SIZE;
+        let slots_needed = size.div_ceil(SLOT_SIZE);
 
         // Find contiguous free slots
         for start_slot in 0..=(NUM_SLOTS - slots_needed) {
@@ -471,7 +471,7 @@ impl LargePayloadSegment {
     /// Free a previously allocated payload
     pub fn free(&self, payload_ref: &PayloadRef) {
         let start_slot = payload_ref.offset as usize / SLOT_SIZE;
-        let slots = (payload_ref.length as usize + SLOT_SIZE - 1) / SLOT_SIZE;
+        let slots = (payload_ref.length as usize).div_ceil(SLOT_SIZE);
 
         for slot in start_slot..(start_slot + slots) {
             let word = slot / 64;
@@ -896,7 +896,7 @@ fn prepare_operation(
     shmem
         .large_payload_segment
         .write(payload_ref.offset as usize, &serialized)
-        .map_err(|e| IpcError::SharedMemoryError(e))?;
+        .map_err(IpcError::SharedMemoryError)?;
 
     Ok((Operation::LargePayloadRef(payload_ref), Some(payload_ref)))
 }

crates/ruvector-postgres/src/workers/maintenance.rs

@@ -177,7 +177,7 @@ pub struct TierCandidate {
 // ============================================================================
 
 /// Maintenance operation statistics
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
 pub struct MaintenanceStats {
     /// Total cycles completed
     pub cycles_completed: u64,
@@ -203,24 +203,6 @@ pub struct MaintenanceStats {
     pub last_cycle_at: u64,
 }
 
-impl Default for MaintenanceStats {
-    fn default() -> Self {
-        Self {
-            cycles_completed: 0,
-            indexes_maintained: 0,
-            compactions_performed: 0,
-            bytes_reclaimed: 0,
-            tier_promotions: 0,
-            tier_demotions: 0,
-            stats_collections: 0,
-            cleanup_operations: 0,
-            total_time_us: 0,
-            last_cycle_duration_us: 0,
-            last_cycle_at: 0,
-        }
-    }
-}
-
 /// Atomic maintenance statistics
 pub struct MaintenanceStatsAtomic {
     cycles_completed: AtomicU64,

crates/ruvector-postgres/src/workers/mod.rs

@@ -131,10 +131,7 @@ impl WorkerRegistry {
     /// Register a new worker
     pub fn register(&self, worker_type: WorkerType, handle: WorkerHandle) {
         let mut workers = self.workers.write();
-        workers
-            .entry(worker_type)
-            .or_insert_with(Vec::new)
-            .push(handle);
+        workers.entry(worker_type).or_default().push(handle);
         self.total_spawned.fetch_add(1, Ordering::SeqCst);
     }
 

crates/ruvector-postgres/src/workers/queue.rs

@@ -74,24 +74,21 @@ impl std::fmt::Display for TaskType {
 }
 
 /// Task priority levels
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
+#[derive(
+    Debug, Clone, Copy, Default, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize,
+)]
 pub enum TaskPriority {
     /// Critical priority - processed immediately
     Critical = 0,
     /// High priority
     High = 1,
     /// Medium priority (default)
+    #[default]
     Medium = 2,
     /// Low priority - background tasks
     Low = 3,
 }
 
-impl Default for TaskPriority {
-    fn default() -> Self {
-        TaskPriority::Medium
-    }
-}
-
 impl std::fmt::Display for TaskPriority {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {