fix(extraction): resolve progressCallback undefined errors

- Add progressCallback parameter to extractFromEmbeddedJSON and extractFromDOM
- Pass onProgress callback from extractWithStrategies to all strategies
- Fix legacy strategy to use correct callback variable name
- Verify extractViaGraphQL correctly returns null thumbnail

This fixes ReferenceError that was preventing all extraction methods from working.
All extraction strategies now properly emit thumbnail progress events via SSE.

Closes: FixProgressCallbackUndefinedErrors

src/lib/server/extraction.ts

@@ -204,7 +204,10 @@ function cleanText(text: string): string {
 /**
  * Strategy 1: Extract from embedded JSON data in script tags
  */
-async function extractFromEmbeddedJSON(page: Page): Promise<ExtractedContent | null> {
+async function extractFromEmbeddedJSON(
+	page: Page,
+	progressCallback?: ProgressCallback
+): Promise<ExtractedContent | null> {
 	try {
 		// Extract all script tag contents
 		const scriptContents = await page.evaluate(() => {
@@ -313,7 +316,10 @@ function extractFromAlternativeStructure(items: any): Omit<ExtractedContent, 'th
 /**
  * Strategy 2: Extract from DOM using specific selectors
  */
-async function extractFromDOM(page: Page): Promise<ExtractedContent | null> {
+async function extractFromDOM(
+	page: Page,
+	progressCallback?: ProgressCallback
+): Promise<ExtractedContent | null> {
 	try {
 		// Strategy: Direct caption selector
 		const captionText = await page.evaluate(() => {
@@ -442,11 +448,11 @@ async function extractWithStrategies(
 	}> = [
 		{
 			name: 'embedded-json',
-			fn: () => extractFromEmbeddedJSON(page)
+			fn: () => extractFromEmbeddedJSON(page, onProgress)
 		},
 		{
 			name: 'dom-selector',
-			fn: () => extractFromDOM(page)
+			fn: () => extractFromDOM(page, onProgress)
 		},
 		{
 			name: 'graphql-api',
@@ -456,7 +462,7 @@ async function extractWithStrategies(
 			name: 'legacy',
 			fn: async () => {
 				const text = await extractCleanTextLegacy(page);
-				const thumbnail = await extractThumbnailStealth(page, progressCallback);
+				const thumbnail = await extractThumbnailStealth(page, onProgress);
 				return { bodyText: text, thumbnail };
 			}
 		}