Initialize atomics in metrics, update style guide on atomics

style.md

@@ -301,6 +301,27 @@ for (auto &precondition : preconditions_) {
 }
 ```
 
+### Atomic Operations
+- **Never use assignment operators** with `std::atomic` - always use explicit `store()` and `load()`
+- **Always specify memory ordering** explicitly for atomic operations
+- **Use the least restrictive correct memory ordering** - choose the weakest ordering that maintains correctness
+```cpp
+// Preferred - explicit store/load with precise memory ordering
+std::atomic<uint64_t> counter;
+counter.store(42, std::memory_order_relaxed);      // Single-writer metric updates
+auto value = counter.load(std::memory_order_relaxed); // Reading metrics for display
+
+counter.store(1, std::memory_order_release);       // Publishing initialization
+auto ready = counter.load(std::memory_order_acquire); // Synchronizing with publisher
+
+counter.store(42, std::memory_order_seq_cst);      // When sequential consistency needed
+
+// Avoid - assignment operators (implicit memory ordering)
+std::atomic<uint64_t> counter;
+counter = 42;        // Implicit - memory ordering not explicit
+auto value = counter; // Implicit - memory ordering not explicit
+```
+
 ---
 
 ## Memory Management