fix: Scan quality — raise page limit, use full DSI text for checks

Bug 1: max_pages was hardcoded to 15 in backend call — raised to 50
Bug 2: DSI documents checked against text_preview (500 chars) — now uses
       full_text (10,000 chars) for Art. 13 mandatory field checks
Bug 3: DSE text not found when Playwright misses DSE page — now falls
       back to DSI Discovery full_text as second source
Bug 4: Backend timeout 120s too short for 50 pages — raised to 300s

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

consent-tester/main.py

@@ -260,6 +260,7 @@ class DSIDocumentInfo(BaseModel):
     doc_type: str = ""
     word_count: int = 0
     text_preview: str = ""
+    full_text: str = ""
 
 
 class DSIDiscoveryResponse(BaseModel):
@@ -311,6 +312,7 @@ async def dsi_discovery(req: DSIDiscoveryRequest):
                 doc_type=d.doc_type,
                 word_count=d.word_count,
                 text_preview=d.text[:500] if d.text else "",
+                full_text=d.text[:10000] if d.text else "",
             )
             for d in result.documents
         ],