🔗 Add URL Content Extraction Feature (#514)

* feat: add URL content extraction for AI diagram generation

* Changes made as recommended by Claude:

1. Added a request timeout to prevent server resources from being tied up (route.ts)
2. Implemented runtime validation for the API response shape (url-utils.ts)
3. Removed hardcoded English error messages and replaced them with localized strings (url-input-dialog.tsx)
4. Fixed the incorrect i18n namespace (changed from pdf.* to url.*) (url-input-dialog.tsx and en/ja/zh.json)

* chore: restore package.json and package-lock.json

* fix: use i18n strings for URL dialog error messages

---------

Co-authored-by: dayuan.jiang <jdy.toh@gmail.com>

components/chat-panel.tsx

@@ -34,6 +34,7 @@ import { findCachedResponse } from "@/lib/cached-responses"
 import { formatMessage } from "@/lib/i18n/utils"
 import { isPdfFile, isTextFile } from "@/lib/pdf-utils"
 import { sanitizeMessages } from "@/lib/session-storage"
+import type { UrlData } from "@/lib/url-utils"
 import { type FileData, useFileProcessor } from "@/lib/use-file-processor"
 import { useQuotaManager } from "@/lib/use-quota-manager"
 import { cn, formatXML, isRealDiagram } from "@/lib/utils"
@@ -158,6 +159,7 @@ export default function ChatPanel({
 
     // File processing using extracted hook
     const { files, pdfData, handleFileChange, setFiles } = useFileProcessor()
+    const [urlData, setUrlData] = useState<Map<string, UrlData>>(new Map())
 
     const [showSettingsDialog, setShowSettingsDialog] = useState(false)
     const [showModelConfigDialog, setShowModelConfigDialog] = useState(false)
@@ -710,6 +712,8 @@ export default function ChatPanel({
                         input,
                         files,
                         pdfData,
+                        undefined,
+                        urlData,
                     )
 
                     setMessages([
@@ -735,6 +739,7 @@ export default function ChatPanel({
                     setInput("")
                     sessionStorage.removeItem(SESSION_STORAGE_INPUT_KEY)
                     setFiles([])
+                    setUrlData(new Map())
                     return
                 }
             }
@@ -755,6 +760,7 @@ export default function ChatPanel({
                     files,
                     pdfData,
                     parts,
+                    urlData,
                 )
 
                 // Add the combined text as the first part
@@ -779,6 +785,7 @@ export default function ChatPanel({
                 setInput("")
                 sessionStorage.removeItem(SESSION_STORAGE_INPUT_KEY)
                 setFiles([])
+                setUrlData(new Map())
             } catch (error) {
                 console.error("Error fetching chart data:", error)
             }
@@ -854,6 +861,7 @@ export default function ChatPanel({
         clearDiagram()
         setDiagramHistory([])
         handleFileChange([]) // Use handleFileChange to also clear pdfData
+        setUrlData(new Map())
         const newSessionId = `session-${Date.now()}-${Math.random()
             .toString(36)
             .slice(2, 9)}`
@@ -972,6 +980,7 @@ export default function ChatPanel({
         files: File[],
         pdfData: Map<File, FileData>,
         imageParts?: any[],
+        urlDataParam?: Map<string, UrlData>,
     ): Promise<string> => {
         let userText = baseText
 
@@ -1002,6 +1011,14 @@ export default function ChatPanel({
             }
         }
 
+        if (urlDataParam) {
+            for (const [url, data] of urlDataParam) {
+                if (data.content) {
+                    userText += `\n\n[URL: ${url}]\nTitle: ${data.title}\n\n${data.content}`
+                }
+            }
+        }
+
         return userText
     }
 
@@ -1264,6 +1281,8 @@ export default function ChatPanel({
                     files={files}
                     onFileChange={handleFileChange}
                     pdfData={pdfData}
+                    urlData={urlData}
+                    onUrlChange={setUrlData}
                     sessionId={sessionId}
                     error={error}
                     models={modelConfig.models}