feat(editor): add image insertion with OCR support and size limit handling

Add image button with dropdown menu for uploading local images or inserting from URL.
Integrate VLM-based OCR to extract text context from images and include in AI suggestions.
Implement document size limits to disable AI when exceeding threshold.
Refactor copilot plugin with per-view runtime state and OCR context injection.
Add OCR cache utility for managing image metadata.
Add code splitting configuration for optimized bundle size.

vite.config.js

@@ -7,6 +7,42 @@ export default defineConfig({
     host: true,
     port: 5173
   },
+  build: {
+    rollupOptions: {
+      output: {
+        manualChunks(id) {
+          if (!id.includes('node_modules')) return
+
+          const modulePath = id.split('node_modules/')[1]
+          const segments = modulePath.split('/')
+          const packageName = segments[0].startsWith('@')
+            ? `${segments[0]}/${segments[1]}`
+            : segments[0]
+
+          if (packageName.startsWith('@milkdown')) return 'milkdown'
+          if (packageName.startsWith('prosemirror')) return 'prosemirror'
+
+          if (packageName.startsWith('@codemirror')) {
+            const langMatch = modulePath.match(/@codemirror\/lang-([^/]+)/)
+            if (langMatch) return `cm-lang-${langMatch[1]}`
+            return `cm-${segments[1]}`
+          }
+
+          if (packageName === 'refractor') {
+            const langMatch = modulePath.match(/refractor\/lang\/([^./]+)/)
+            if (langMatch) return `refractor-lang-${langMatch[1]}`
+            return 'refractor-core'
+          }
+
+          if (packageName.startsWith('katex')) return 'katex'
+          if (packageName.startsWith('markdown-it')) return 'markdown'
+          if (packageName === 'vue' || packageName.startsWith('@vue')) return 'vue'
+
+          return `vendor-${packageName.replace('@', '').replace('/', '-')}`
+        }
+      }
+    }
+  },
   optimizeDeps: {
     include: [
       '@milkdown/crepe',