feat(plugin): implement canvas node plugin system with dynamic registration and remote installation

plugins/canvas/markdown/README.md

@@ -0,0 +1,23 @@
+# Markdown 节点插件
+
+Infinite Canvas 画布节点插件:在画布里编辑与渲染 Markdown。
+
+## 构建
+
+```bash
+npm install
+npm run build      # 产物 dist/markdown.js,并同步到 web/public/plugins/markdown.js
+npm run dev        # watch,改动自动构建
+```
+
+## 安装
+
+画布 → 左上菜单「节点插件」→ 安装 URL 填 `/plugins/markdown.js`(或托管后的公网 URL)。
+
+## 本地开发
+
+`npm run dev` 起 watch,在 `web/.env.local` 加 `VITE_DEV_PLUGINS=/plugins/markdown.js`,起画布后改 `src/index.jsx` 刷新页面即生效,无需反复安装。
+
+插件契约见 `plugins/canvas/README.md`。
+
+> 本插件演示了独立 CSS 文件用法:`src/styles.css` 经 esbuild `text` loader 打进 bundle,通过插件 `css` 字段自动注入/清理。

plugins/canvas/markdown/build.mjs

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+import { build, context } from "esbuild";
+import { cp, mkdir } from "node:fs/promises";
+import { basename, dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const root = dirname(fileURLToPath(import.meta.url));
+const name = basename(root); // 目录名即插件产物名,如 markdown → markdown.js
+const distDir = join(root, "dist");
+// 本地开发同步到 web/public/plugins,便于用 /plugins/<name>.js 安装或走 VITE_DEV_PLUGINS
+const publicDir = join(root, "..", "..", "..", "web", "public", "plugins");
+const watch = process.argv.includes("--watch");
+
+const syncToPublic = {
+    name: "sync-to-public",
+    setup(builder) {
+        builder.onEnd(async (result) => {
+            if (result.errors.length) return;
+            await mkdir(publicDir, { recursive: true });
+            await cp(join(distDir, `${name}.js`), join(publicDir, `${name}.js`));
+            console.log(`[${name}] synced → web/public/plugins/${name}.js`);
+        });
+    },
+};
+
+const options = {
+    entryPoints: [join(root, "src", "index.jsx")],
+    outfile: join(distDir, `${name}.js`),
+    bundle: true,
+    format: "esm",
+    platform: "browser",
+    target: "es2020",
+    // 经典 JSX 转换 → React.createElement,使用源码里 runtime 解构出的 React
+    jsx: "transform",
+    jsxFactory: "React.createElement",
+    jsxFragment: "React.Fragment",
+    loader: { ".js": "jsx", ".jsx": "jsx", ".css": "text" },
+    // 通过 runtime.React 使用宿主 React,自身不打包 React
+    external: ["react", "react-dom"],
+    minify: !watch,
+    plugins: [syncToPublic],
+};
+
+if (watch) {
+    const ctx = await context(options);
+    await ctx.watch();
+    console.log(`[${name}] watching src/ ...`);
+} else {
+    await build(options);
+    console.log(`[${name}] built → dist/${name}.js`);
+}

plugins/canvas/markdown/package-lock.json

@@ -0,0 +1,499 @@
+{
+    "name": "canvas-plugin-markdown",
+    "version": "1.0.0",
+    "lockfileVersion": 3,
+    "requires": true,
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+        "": {
+            "name": "canvas-plugin-markdown",
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+                "@esbuild/freebsd-x64": "0.25.12",
+                "@esbuild/linux-arm": "0.25.12",
+                "@esbuild/linux-arm64": "0.25.12",
+                "@esbuild/linux-ia32": "0.25.12",
+                "@esbuild/linux-loong64": "0.25.12",
+                "@esbuild/linux-mips64el": "0.25.12",
+                "@esbuild/linux-ppc64": "0.25.12",
+                "@esbuild/linux-riscv64": "0.25.12",
+                "@esbuild/linux-s390x": "0.25.12",
+                "@esbuild/linux-x64": "0.25.12",
+                "@esbuild/netbsd-arm64": "0.25.12",
+                "@esbuild/netbsd-x64": "0.25.12",
+                "@esbuild/openbsd-arm64": "0.25.12",
+                "@esbuild/openbsd-x64": "0.25.12",
+                "@esbuild/openharmony-arm64": "0.25.12",
+                "@esbuild/sunos-x64": "0.25.12",
+                "@esbuild/win32-arm64": "0.25.12",
+                "@esbuild/win32-ia32": "0.25.12",
+                "@esbuild/win32-x64": "0.25.12"
+            }
+        }
+    }
+}

plugins/canvas/markdown/package.json

@@ -0,0 +1,14 @@
+{
+    "name": "canvas-plugin-markdown",
+    "version": "1.0.0",
+    "private": true,
+    "type": "module",
+    "description": "Infinite Canvas Markdown 节点插件",
+    "scripts": {
+        "build": "node build.mjs",
+        "dev": "node build.mjs --watch"
+    },
+    "devDependencies": {
+        "esbuild": "^0.25.0"
+    }
+}

plugins/canvas/markdown/src/index.jsx

@@ -0,0 +1,64 @@
+// Markdown 节点:编辑与渲染 Markdown。marked 从 CDN 按需加载,不打进插件体积。
+// styles.css 由 esbuild 以 text 方式打进 bundle,通过 plugin.css 自动注入。
+import css from "./styles.css";
+
+let markedPromise;
+function loadMarked() {
+    if (!markedPromise) markedPromise = import("https://esm.sh/marked@14").then((mod) => mod.marked);
+    return markedPromise;
+}
+
+export default function markdownPlugin(runtime) {
+    const { React } = runtime;
+    const { useState, useEffect } = React;
+
+    function MarkdownContent({ ctx }) {
+        const [editing, setEditing] = useState(false);
+        const [html, setHtml] = useState("");
+        const value = ctx.node.metadata?.content || "";
+
+        useEffect(() => {
+            let alive = true;
+            loadMarked().then((marked) => {
+                if (alive) setHtml(marked.parse(value || "*双击右上角按钮编辑 Markdown*"));
+            });
+            return () => {
+                alive = false;
+            };
+        }, [value]);
+
+        const toggle = { position: "absolute", right: 8, top: 8, zIndex: 20, width: 32, height: 32, display: "grid", placeItems: "center", borderRadius: 8, border: `1px solid ${ctx.theme.node.stroke}`, background: `${ctx.theme.toolbar.panel}dd`, color: ctx.theme.node.text, cursor: "pointer" };
+
+        return (
+            <div data-canvas-no-zoom onMouseDown={(e) => e.stopPropagation()} style={{ position: "relative", height: "100%", width: "100%", display: "flex", flexDirection: "column" }}>
+                <button type="button" style={toggle} onClick={() => setEditing((v) => !v)} title={editing ? "预览" : "编辑"}>{editing ? "👁" : "✎"}</button>
+                {editing ? (
+                    <textarea autoFocus value={value} placeholder="# 输入 Markdown" onChange={(e) => ctx.updateMetadata({ content: e.target.value })} onWheel={(e) => e.stopPropagation()} style={{ height: "100%", width: "100%", resize: "none", background: "transparent", padding: 16, fontFamily: "monospace", fontSize: 14, outline: "none", border: "none", color: ctx.theme.node.text }} />
+                ) : (
+                    <div className="cnv-md" onWheel={(e) => e.stopPropagation()} style={{ color: ctx.theme.node.text }} dangerouslySetInnerHTML={{ __html: html }} />
+                )}
+            </div>
+        );
+    }
+
+    return {
+        id: "markdown",
+        name: "Markdown 节点",
+        version: "1.0.0",
+        description: "在画布中编辑与渲染 Markdown",
+        css,
+        nodes: [
+            {
+                type: "markdown:doc",
+                title: "Markdown",
+                icon: "📝",
+                description: "编辑与渲染 Markdown",
+                defaultSize: { width: 360, height: 300 },
+                defaultMetadata: { content: "" },
+                minimapColor: "#6366f1",
+                resource: (node) => ({ kind: "text", text: node.metadata?.content }),
+                Content: MarkdownContent,
+            },
+        ],
+    };
+}

plugins/canvas/markdown/src/styles.css

@@ -0,0 +1,59 @@
+.cnv-md {
+    height: 100%;
+    width: 100%;
+    overflow: auto;
+    padding: 16px;
+    font-size: 14px;
+    line-height: 1.6;
+}
+.cnv-md h1,
+.cnv-md h2,
+.cnv-md h3 {
+    margin: 0.6em 0 0.3em;
+    font-weight: 600;
+    line-height: 1.3;
+}
+.cnv-md h1 {
+    font-size: 1.5em;
+}
+.cnv-md h2 {
+    font-size: 1.3em;
+}
+.cnv-md p {
+    margin: 0.5em 0;
+}
+.cnv-md a {
+    color: #6366f1;
+    text-decoration: underline;
+}
+.cnv-md code {
+    padding: 0.1em 0.35em;
+    border-radius: 4px;
+    background: rgba(120, 120, 120, 0.16);
+    font-family: monospace;
+    font-size: 0.9em;
+}
+.cnv-md pre {
+    padding: 12px;
+    border-radius: 8px;
+    background: rgba(120, 120, 120, 0.14);
+    overflow: auto;
+}
+.cnv-md pre code {
+    padding: 0;
+    background: transparent;
+}
+.cnv-md ul,
+.cnv-md ol {
+    padding-left: 1.4em;
+    margin: 0.5em 0;
+}
+.cnv-md blockquote {
+    margin: 0.5em 0;
+    padding-left: 0.8em;
+    border-left: 3px solid rgba(120, 120, 120, 0.4);
+    opacity: 0.85;
+}
+.cnv-md img {
+    max-width: 100%;
+}