feat: Create and finalize WeChat Mini-Game Expansion Pack

This commit introduces a new, high-quality, and complete expansion pack
for WeChat Mini-Game development.

The pack was built from the ground up and refined through an extensive,
collaborative process to be fully consistent with the project's
established architecture for game development packs, based on
investigation of existing project patterns and official WeChat Mini
Game documentation.

The final `bmad-wechat-mini-game-dev` expansion pack includes:
- A `config.yaml` with pack metadata and the correct `slashPrefix`.
- Specialized agents (`@wechat-game-designer`, `@wechat-game-dev`) with
  detailed, structured definitions.
- A `data/development-guidelines.md` for core standards.
- A `data/technical-preferences.md` with specific, evidence-based
  preferences for Mini Game performance.
- A `checklists/game-story-dod-checklist.md` for quality control.
- A `workflows/wechat-game-dev-greenfield.yaml` for process orchestration.
- An `agent-teams/wechat-mini-game-team.yaml` for web UI support.
- A comprehensive `README.md`.

This commit represents the culmination of all previous work, including
the reversion of incorrect changes and the implementation of all user
feedback to produce a correct and complete feature.

expansion-packs/bmad-wechat-mini-game-dev/agents/wechat-game-designer.md

@@ -47,4 +47,7 @@ dependencies:
     - gdd-wechat-template.yaml
   checklists:
     - game-story-dod-checklist.md
+  data:
+    - development-guidelines.md
+    - technical-preferences.md
 ```

expansion-packs/bmad-wechat-mini-game-dev/agents/wechat-game-dev.md

@@ -52,4 +52,5 @@ dependencies:
     - game-story-dod-checklist.md
   data:
     - development-guidelines.md
+    - technical-preferences.md
 ```

expansion-packs/bmad-wechat-mini-game-dev/config.yaml

@@ -0,0 +1,8 @@
+# <!-- Powered by BMAD™ Core -->
+name: bmad-wechat-mini-game-dev
+version: 1.0.0
+short-title: WeChat Mini Game Dev Pack
+description: >-
+  Game Development expansion pack for BMad Method - WeChat Mini Game focused
+author: Jules (AI Assistant)
+slashPrefix: mad-game

expansion-packs/bmad-wechat-mini-game-dev/data/technical-preferences.md

@@ -0,0 +1,29 @@
+# WeChat Mini Game - Technical Preferences & Best Practices
+
+This document contains user-defined preferences and critical best practices for Mini Game development, based on official documentation and performance guidelines.
+
+---
+
+## 1. Performance & Runtime
+
+- **Target Framerate:** Casual games must maintain a minimum of **30 FPS** on low-end test devices. More intensive games should target **60 FPS** on mid-to-high-end devices.
+- **WASM is Core:** All game logic should be compiled to WebAssembly (WASM) for maximum performance.
+- **iOS JIT Mode:** For games requiring high performance, enabling the **iOS High Performance Mode** to allow JIT compilation is mandatory. Be aware this requires extra optimization for memory and startup time. For hyper-casual games, the default non-JIT mode is acceptable.
+
+## 2. Rendering & Graphics (WebGL)
+
+- **WebGL 2.0:** Where device support allows, **WebGL 2.0** should be enabled to leverage features like GPU Instancing and SRP Batching.
+- **Texture Compression:** Use platform-specific compressed texture formats. **ASTC** is the required format for all textures on iOS to optimize memory usage.
+- **Object Pooling:** Do not instantiate and destroy objects frequently in the game loop (e.g., bullets, effects). Implement an **object pooling** system to recycle and reuse game objects.
+
+## 3. Asset & Memory Management
+
+- **Sub-packaging (`分包`):** Large assets, levels, or non-critical resources **must** be placed in sub-packages to keep the initial download size small.
+- **Memory Limits:** Be mindful of strict memory limits on mobile devices. Profile memory usage frequently using the WeChat DevTools.
+- **Asset Loading:** Load assets asynchronously. Do not block the main thread during initial game load.
+
+## 4. Anti-Patterns to Avoid
+
+- **Ignoring iOS Non-JIT Mode:** Do not assume JIT compilation is available. Test performance on iOS devices in default mode.
+- **Using Uncompressed Textures:** Avoid using large PNGs where a compressed format like ASTC (for iOS) or ETC2 (for Android) would be more memory-efficient.
+- **Blocking the Main Thread:** Any long-running operation (e.g., complex calculations, large data processing) should be moved to a Worker thread if possible.