fix: restore missing cpp-pro reference documentation (Issue #382) (#383)

* fix: restore missing cpp-pro reference documentation (Issue #382)

* docs: restore implementation-playbook with idiomatic C++ patterns

* Update implementation-playbook.md

* Update implementation-playbook.md

skills/cpp-pro/resources/implementation-playbook.md

@@ -0,0 +1,43 @@
+# C++ Implementation Playbook
+
+**Date:** March 23, 2026  
+**Author:** champbreed  
+---
+
+## 1. RAII & Resource Management
+Always wrap raw resources in manager objects to ensure cleanup on scope exit.
+```cpp
+// Good: Scope-bound cleanup
+void process() {
+    auto data = std::make_unique<uint8_t[]>(1024);
+    // memory is freed automatically
+}
+```
+## 2. Smart Pointer Ownership
+- **unique_ptr**: Use for exclusive ownership.
+- **shared_ptr**: Use for shared ownership across components.
+- **weak_ptr**: Use to break circular reference cycles.
+
+## 3. Concurrency Safety
+Always use RAII-style locks like `std::lock_guard` or `std::unique_lock`.
+```cpp
+void update() {
+    std::lock_guard<std::mutex> lock(mutex_); // Released automatically
+    // thread-safe logic
+}
+```
+## 4. Move Semantics & Efficiency
+Avoid expensive copies by utilizing move constructors and `std::move`.
+```cpp
+void processData(std::vector<std::string>&& data) {
+    auto internalData = std::move(data); // Transfers ownership, no copy
+}
+```
+## 5. Modern STL Algorithms
+Prefer algorithms over manual loops for readability and optimization.
+
+```cpp
+void sortData(std::vector<int>& myVector) {
+    // Use std::ranges (C++20) for cleaner, safer iteration
+    std::ranges::sort(myVector);
+}