feat: add Sprite Merger documentation and Inset Crop Tool integration

- Added comprehensive documentation for Sprite Merger tool (both Chinese and English)
- Added Inset Crop Tool documentation with real-time preview feature
- Updated project structure and API endpoints sections
- Integrated Inset Crop Tool with background removal and intelligent cropping
- Updated navigation and tool registry in tool.py
- All documentation reflects both new features and complete tool suite

tool.py

@@ -10,6 +10,7 @@ from sprite_webtool import app as picker_app
 from shiny_maker import app as shiny_app
 from rotate_webtool import app as flipper_app
 from sprite_merger import app as merger_app
+from inset_crop_tool import app as inset_app
 
 app = FastAPI(title="Game Dev Suite")
 
@@ -23,6 +24,7 @@ NAVBAR_HTML = """
     <a href="/shiny/" class="text-sm text-slate-300 hover:text-blue-400 transition">✨ Shiny Maker</a>
     <a href="/flipper/" class="text-sm text-slate-300 hover:text-blue-400 transition">🔄 Flipper</a>
     <a href="/merger/" class="text-sm text-slate-300 hover:text-blue-400 transition">🧩 Merger</a>
+    <a href="/inset/" class="text-sm text-slate-300 hover:text-blue-400 transition">✂️ Inset Crop</a>
 </nav>
 """
 
@@ -58,6 +60,7 @@ app.mount("/picker", picker_app)
 app.mount("/shiny", shiny_app)
 app.mount("/flipper", flipper_app)
 app.mount("/merger", merger_app)
+app.mount("/inset", inset_app)
 
 # 首頁入口
 @app.get("/", response_class=HTMLResponse)
@@ -80,6 +83,7 @@ async def index():
                 <a href="/shiny/" class="p-6 bg-slate-800 rounded-2xl border border-slate-700 text-center hover:border-blue-500 transition block">✨ Shiny Maker</a>
                 <a href="/flipper/" class="p-6 bg-slate-800 rounded-2xl border border-slate-700 text-center hover:border-blue-500 transition block">🔄 Flipper</a>
                 <a href="/merger/" class="p-6 bg-slate-800 rounded-2xl border border-slate-700 text-center hover:border-blue-500 transition block">🧩 Merger</a>
+                <a href="/inset/" class="p-6 bg-slate-800 rounded-2xl border border-slate-700 text-center hover:border-blue-500 transition block">✂️ Inset Crop</a>
             </div>
         </div>
     </body>