Add third batch of Web SDK demos to THEOplayer examples

[devin-ai-integration]

Summary

Migrates ten legacy Web SDK demos into /theoplayer/examples/ using the existing Example + utils.js iframe pattern, and points the relevant docs at the new pages (changelogs untouched). No demo autoplays on page load.

New pages:

• ads/02-advertisement-tester: merges both old ad tester demos. One Open Video UI player, an "Ad templates" dropdown (VAST pre/mid/post-roll, VMAP, Google IMA, Google IMA with companion ad, Google IMA SIMID, non-linear, VPAID), and an editable configuration (video URL with .mpd/.m3u8 type inference, ad URL, integration, position, time offset). The generated code also shows how to insert an ad at runtime with player.ads.schedule(). The page has a compact ad event log, and companion ads from ad.companions are rendered using only resourceURI/clickThrough/altText, never contentHTML.
• ads/03-ad-block-detection: toggles blockContentIfAdError with the Google sample ad tag, and shows the Message and Content readout from player.ads aderror and player error.
• ui/04-related-content (Open Video UI + Default UI): a "Related content" menu with tiles in Open Video UI, and player.related.sources in Default UI. Both open directly on ended: Default UI calls player.related.show(), and Open Video UI calls click() on the existing <theoplayer-menu-button> when #related-menu is still hidden, so no non-public menu API is needed.
• ui/05-social-sharing (Open Video UI + Default UI): player.social in Default UI. In Open Video UI, a share menu with a translucent overlay covers the whole player and is closed with the menu's built-in back button.
• ui/06-preview-thumbnails: toggles between in-manifest DASH tiled thumbnails and a side-loaded WebVTT thumbnails metadata track.
• playback/06-preload: switches preload between none/metadata/auto and shows the buffer with RangeBar. Each switch re-creates the player: player.destroy(), then a new <theoplayer-default-ui>, and player.preload is set before player.source.
• playback/07-playlist-and-caching: three-item playlist. It caches the next item with THEOplayer.cache.createTask(next, { amount: '25%' }) at 75% playback or on demand, and reuses any existing task for the same source from THEOplayer.cache.tasks (tasks persist across reloads), so no duplicate tasks are created.
• streaming/07-network-api: request/response interceptor log with filters, pause and clear, plus optional VTT text reversal via response.respondWith(), which handles both string and ArrayBuffer bodies.

Extended existing pages instead of adding new ones:

• ui/01-adding-buttons: ±10 s seek buttons (<theoplayer-seek-button seek-offset="±10"> in Open Video UI, two video.js Button components in Default UI).
• ui/02-changing-ui-with-css: every UI skinning option can now be set separately (Default UI primary/secondary/tertiary color and background classes plus .vjs-selected; Open Video UI custom properties), with live generated CSS.

Link to Devin session: https://dolby.devinenterprise.com/sessions/b936a9a57363474d901aed6902718cc2
Open in Devin Desktop: https://dolby.devinenterprise.com/desktop/session/b936a9a57363474d901aed6902718cc2?variant=devin

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring