docs: follow the asset publication through the documents that described it

Committing the store assets changed a rule that four files stated, so they now state the new one
instead of contradicting the tree:

- STORE_LISTING: "screenshots are not committed" becomes what is committed, why it is safe (every
  published frame is generated demo content), and what is still deliberately out of git (raw
  captures, demo photos, the video's milestone PNGs). It also spells out the public URL pattern,
  because that is now the deployment step rather than a footnote.
- PLAY_RELEASE_CHECKLIST: the two "(git-ignored)" annotations on the screenshot directories become
  "(committed)", and step 5's video item carries the exact link to paste plus what was verified
  about it (200, video/mp4, Content-Disposition: inline, sha256 match) and the two traps in using
  it (pinned to main, so a re-shoot overwrites in place; and replacing it at all means resubmitting
  the declaration).
- ROADMAP: M10 no longer claims the screenshots are left uncommitted, and the declaration's blocker
  row loses its "hosting remains" clause - the file is published, so only pasting is left.
- README: says where the link comes from, so the next reader does not go looking for a host.

README.md

@@ -190,7 +190,10 @@ selects the 7-inch pipeline, and the tablet runs deliberately crop no system chr
 tablet frame is already inside Play's 2:1 cap. All three sets are captured — the phone set on a real
 device, the tablet sets on AOSP AVDs; see [docs/STORE_LISTING.md](docs/STORE_LISTING.md).
 `python3 tools/make-demo-photos.py` draws the synthetic photo library the results screenshot is
-captured over, so the listing never shows a real one.
+captured over, so the listing never shows a real one. The finished assets are **committed** —
+including the foreground-service demonstration video that [the declaration](docs/PLAY_RELEASE_CHECKLIST.md)
+links to — and Gitea serves them without a login (`…/raw/branch/main/store-assets/…`), so pushing
+is the deployment step and that URL is the link itself.
 
 User-visible changes are tracked in [CHANGELOG.md](CHANGELOG.md); the Play "What's new"
 text you type per release is separate and lives only in the Play Console.