Improve scripts for youtube/subtitltles/thumbnails (#280)

* Update thumbnail generation

* Improve resiliency of the script

* Move to OpenRouter and add filters

* Add exclude id to subtitle upload

* Fix yt to openplanner

* Address Copilot review on scripts

- youtubeAPI: guard undefined playlist items before spread
- youtubeBatchEdit: derive tag year from session date, not run date
- youtubeSubtitleEdit: fix OPENROUTER_MODEL default in doc comment
- thumbnails README: fix background asset link .jpg -> .png

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: HugoGresse

scripts/.env.example

@@ -1,5 +1,14 @@
 YOUTUBE_PLAYLIST_ID=YOUTUBE_PLAYLIST_ID
 OPENPLANNER_EVENT_ID=
 OPENPLANNER_API_KEY=
+
+# Speech-to-text (youtubeSubtitleEdit.js)
 GLADIA_API_KEY=
-OPENAI_API_KEY=
+GLADIA_MODEL=solaria-3
+
+# Keyword extraction via OpenRouter (youtubeSubtitleEdit.js)
+OPENROUTER_API_KEY=
+OPENROUTER_MODEL=z-ai/glm-5.2
+
+# Thumbnails source dir for youtubeBatchEdit.js (defaults to youtube-thumbnails/output/<eventId>)
+THUMBNAILS_DIR=