feat: 品牌升级(知冶→战知) + 应用工具广场重构 + 新增工具集成

品牌升级：
- 全站品牌从"知冶"更名为"战知"
- 更换 favicon、侧边栏 logo、登录页 logo
- 更新登录页标语和首页欢迎语

应用广场重构：
- 从后端数据库驱动改为前端静态配置，按分类 tab 展示
- 新增工具卡片 UI，支持 logo 图片和 emoji 图标

新增工具部署：
- Stirling PDF (端口18080) - PDF 处理工具箱
- Excalidraw (端口18081) - 手绘风格白板，集成 AI 绘图
- TrWebOCR (端口18083) - 中文离线 OCR
- LibreTranslate (端口18084) - 中英翻译引擎
- PPTist (端口18085) - 在线 PPT 编辑器
- PPTist AI 后端 (端口18086) - 对接 deepseek-v3 生成大纲/PPT/写作
- Excalidraw AI 代理 (端口18082) - 对接 deepseek-v3 生成 Mermaid 图

其他：
- 智能场景仅保留"选题推荐"
- vite 代理配置增加 /pdf/ 和 /draw/ 路由

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/excalidraw-ai-proxy.py

@@ -0,0 +1,98 @@
+"""
+Excalidraw AI 代理服务
+接收 Excalidraw 的 text-to-diagram 请求，转发给 deepseek-v3 生成 Mermaid 语法
+"""
+from fastapi import FastAPI, Request
+from fastapi.middleware.cors import CORSMiddleware
+import requests
+import json
+
+app = FastAPI()
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+LLM_API = "http://10.102.24.75:3000/v1/chat/completions"
+LLM_KEY = "sk-BlQIGRrotbVDWE5mXCPBFjVWIvJ83hldzz67xInNwzVo7pPb"
+
+SYSTEM_PROMPT = """You are an expert at creating Mermaid diagrams.
+When the user describes a diagram, workflow, flowchart, or similar,
+generate ONLY valid Mermaid syntax. Do not include any explanation,
+just the Mermaid code. Do not wrap it in markdown code blocks.
+Always start with a diagram type declaration like: graph TD, flowchart LR, sequenceDiagram, classDiagram, etc."""
+
+
+@app.post("/v1/ai/text-to-diagram/generate")
+async def text_to_diagram(request: Request):
+    body = await request.json()
+    print(f"[AI] Received request: {json.dumps(body, ensure_ascii=False)[:500]}")
+    prompt = body.get("prompt", body.get("text", body.get("message", "")))
+
+    try:
+        resp = requests.post(LLM_API, json={
+            "model": "deepseek-v3",
+            "messages": [
+                {"role": "system", "content": SYSTEM_PROMPT},
+                {"role": "user", "content": prompt}
+            ],
+            "temperature": 0.3,
+            "max_tokens": 2048
+        }, headers={"Authorization": f"Bearer {LLM_KEY}"}, timeout=60)
+
+        result = resp.json()
+        print(f"[AI] LLM response status: {resp.status_code}")
+        mermaid_code = result["choices"][0]["message"]["content"].strip()
+
+        # 清理可能的 markdown 包裹
+        if mermaid_code.startswith("```"):
+            mermaid_code = mermaid_code.split("\n", 1)[1] if "\n" in mermaid_code else mermaid_code[3:]
+        if mermaid_code.endswith("```"):
+            mermaid_code = mermaid_code[:-3].strip()
+
+        print(f"[AI] Mermaid output: {mermaid_code[:200]}")
+        return {"generatedResponse": mermaid_code}
+    except Exception as e:
+        print(f"[AI] Error: {e}")
+        return {"generatedResponse": f"graph TD\n    A[Error: {str(e)[:50]}]"}
+
+
+@app.post("/v1/ai/diagram-to-code/generate")
+async def diagram_to_code(request: Request):
+    body = await request.json()
+    texts = body.get("texts", [])
+    theme = body.get("theme", "light")
+    print(f"[AI] diagram-to-code request, texts: {texts[:5]}, theme: {theme}")
+
+    prompt = f"Based on these UI element labels: {', '.join(texts) if texts else 'empty wireframe'}. Theme: {theme}. Generate a complete, beautiful HTML page with inline CSS that represents this wireframe layout. Only output the HTML code, nothing else."
+
+    try:
+        resp = requests.post(LLM_API, json={
+            "model": "deepseek-v3",
+            "messages": [
+                {"role": "system", "content": "You are an expert web developer. Generate complete HTML with inline CSS based on wireframe descriptions. Output ONLY the HTML code, no explanation, no markdown code blocks."},
+                {"role": "user", "content": prompt}
+            ],
+            "temperature": 0.3,
+            "max_tokens": 4096
+        }, headers={"Authorization": f"Bearer {LLM_KEY}"}, timeout=60)
+
+        result = resp.json()
+        html_code = result["choices"][0]["message"]["content"].strip()
+        if html_code.startswith("```"):
+            html_code = html_code.split("\n", 1)[1] if "\n" in html_code else html_code[3:]
+        if html_code.endswith("```"):
+            html_code = html_code[:-3].strip()
+        print(f"[AI] HTML output length: {len(html_code)}")
+        return html_code
+    except Exception as e:
+        print(f"[AI] diagram-to-code error: {e}")
+        return f"<html><body><h1>Generation Error</h1><p>{str(e)[:100]}</p></body></html>"
+
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run(app, host="0.0.0.0", port=18082)