fix: resolve URL loading timeout issues in @ mentions

## Problem
URLs provided through @ mentions were failing to load with "Navigation timeout of 10000 ms exceeded" errors, preventing users from fetching web content for AI assistance.

## Solution
- **Increased timeout limits**: Extended UrlContentFetcher timeout from 10s to 30s and BrowserSession timeout from 7s to 15s for better reliability with slow-loading websites
- **Added fallback retry logic**: If networkidle2 fails, automatically retry with domcontentloaded only (20s timeout) to handle JavaScript-heavy sites
- **Improved error handling**: Enhanced error messages with specific guidance for timeout, DNS, network, and HTTP status errors
- **Enhanced browser compatibility**: Added Chrome launch arguments (--no-sandbox, --disable-web-security, etc.) and set proper viewport/headers to reduce blocking by websites

## Files Changed
- `src/services/browser/UrlContentFetcher.ts`: Increased timeout, added retry logic, enhanced browser setup
- `src/services/browser/BrowserSession.ts`: Increased navigation timeouts for consistency
- `src/core/mentions/index.ts`: Improved error handling with user-friendly messages

## Impact
Users can now successfully fetch content from slower websites and receive clearer error messages when issues occur, significantly improving the @ mention URL feature reliability.

Fixes #1430

Author: MuriloFP

src/core/mentions/index.ts

@@ -98,8 +98,24 @@ export async function parseMentions(
 					const markdown = await urlContentFetcher.urlToMarkdown(mention)
 					result = markdown
 				} catch (error) {
-					vscode.window.showErrorMessage(`Error fetching content for ${mention}: ${error.message}`)
-					result = `Error fetching content: ${error.message}`
+					console.error(`Error fetching URL ${mention}:`, error)
+
+					// Provide more helpful error messages based on error type
+					let errorMessage = error.message
+					if (error.message.includes("timeout")) {
+						errorMessage = `The website took too long to load (timeout). This could be due to a slow connection, heavy website, or the site being temporarily unavailable. You can try again later or check if the URL is correct.`
+					} else if (error.message.includes("net::ERR_NAME_NOT_RESOLVED")) {
+						errorMessage = `The website address could not be found. Please check if the URL is correct and try again.`
+					} else if (error.message.includes("net::ERR_INTERNET_DISCONNECTED")) {
+						errorMessage = `No internet connection. Please check your network connection and try again.`
+					} else if (error.message.includes("403") || error.message.includes("Forbidden")) {
+						errorMessage = `Access to this website is forbidden. The site may block automated access or require authentication.`
+					} else if (error.message.includes("404") || error.message.includes("Not Found")) {
+						errorMessage = `The page was not found. Please check if the URL is correct.`
+					}
+
+					vscode.window.showErrorMessage(`Error fetching content for ${mention}: ${errorMessage}`)
+					result = `Error fetching content: ${errorMessage}`
 				}
 			}
 			parsedText += `\n\n<url_content url="${mention}">\n${result}\n</url_content>`

src/services/browser/BrowserSession.ts

@@ -320,7 +320,7 @@ export class BrowserSession {
 	 * Navigate to a URL with standard loading options
 	 */
 	private async navigatePageToUrl(page: Page, url: string): Promise<void> {
-		await page.goto(url, { timeout: 7_000, waitUntil: ["domcontentloaded", "networkidle2"] })
+		await page.goto(url, { timeout: 15_000, waitUntil: ["domcontentloaded", "networkidle2"] })
 		await this.waitTillHTMLStable(page)
 	}
 
@@ -403,7 +403,7 @@ export class BrowserSession {
 				console.log(`Root domain: ${this.getRootDomain(currentUrl)}`)
 				console.log(`New URL: ${normalizedNewUrl}`)
 				return this.doAction(async (page) => {
-					await page.reload({ timeout: 7_000, waitUntil: ["domcontentloaded", "networkidle2"] })
+					await page.reload({ timeout: 15_000, waitUntil: ["domcontentloaded", "networkidle2"] })
 					await this.waitTillHTMLStable(page)
 				})
 			}
@@ -476,7 +476,7 @@ export class BrowserSession {
 			await page
 				.waitForNavigation({
 					waitUntil: ["domcontentloaded", "networkidle2"],
-					timeout: 7000,
+					timeout: 15000,
 				})
 				.catch(() => {})
 			await this.waitTillHTMLStable(page)

src/services/browser/UrlContentFetcher.ts

@@ -48,11 +48,28 @@ export class UrlContentFetcher {
 		this.browser = await stats.puppeteer.launch({
 			args: [
 				"--user-agent=Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36",
+				"--no-sandbox",
+				"--disable-setuid-sandbox",
+				"--disable-dev-shm-usage",
+				"--disable-accelerated-2d-canvas",
+				"--no-first-run",
+				"--no-zygote",
+				"--disable-gpu",
+				"--disable-web-security",
+				"--disable-features=VizDisplayCompositor",
 			],
 			executablePath: stats.executablePath,
 		})
 		// (latest version of puppeteer does not add headless to user agent)
 		this.page = await this.browser?.newPage()
+
+		// Set additional page configurations to improve loading success
+		if (this.page) {
+			await this.page.setViewport({ width: 1280, height: 720 })
+			await this.page.setExtraHTTPHeaders({
+				"Accept-Language": "en-US,en;q=0.9",
+			})
+		}
 	}
 
 	async closeBrowser(): Promise<void> {
@@ -71,7 +88,22 @@ export class UrlContentFetcher {
 		- domcontentloaded is when the basic DOM is loaded
 		this should be sufficient for most doc sites
 		*/
-		await this.page.goto(url, { timeout: 10_000, waitUntil: ["domcontentloaded", "networkidle2"] })
+		try {
+			await this.page.goto(url, {
+				timeout: 30_000, // Increased from 10_000 to 30_000 (30 seconds)
+				waitUntil: ["domcontentloaded", "networkidle2"],
+			})
+		} catch (error) {
+			// If networkidle2 fails, try with just domcontentloaded as fallback
+			console.warn(
+				`Failed to load ${url} with networkidle2, retrying with domcontentloaded only: ${error.message}`,
+			)
+			await this.page.goto(url, {
+				timeout: 20_000, // 20 seconds for fallback
+				waitUntil: ["domcontentloaded"],
+			})
+		}
+
 		const content = await this.page.content()
 
 		// use cheerio to parse and clean up the HTML