fix(tecdoc): only surface publicly-resolvable part images

The snapshot stores scrape-local '/_debug/...' image paths that 404
off-host. Filter the OEM lookup to http(s) image URLs and render the
thumbnail only when one exists, so the detail page shows clean
code-focused cards instead of a grid of broken-image placeholders.
Real CDN URLs will surface automatically once present.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/api/src/integrations/tecdoc/tecdoc-source-db.service.ts

@@ -128,8 +128,13 @@ export class TecdocSourceDbService implements OnModuleInit, OnModuleDestroy {
           COALESCE((
             SELECT json_agg(json_build_object('url', i.image_url, 'thumb', i.thumb_url) ORDER BY i.sort_order)
             FROM (
+              -- Only publicly-resolvable URLs. The current snapshot stores
+              -- scrape-local '/_debug/...' paths (404 off-host) — filtering them
+              -- here keeps the API contract honest so the UI shows no broken
+              -- thumbnails; real CDN URLs surface automatically once present.
               SELECT image_url, thumb_url, sort_order FROM article_images
-              WHERE article_id = a.id ORDER BY sort_order LIMIT 8
+              WHERE article_id = a.id AND image_url LIKE 'http%'
+              ORDER BY sort_order LIMIT 8
             ) i
           ), '[]') AS images,
           COALESCE((