fix(ci): correct fastlane metadata path; park the unsupported bs listing

[emir-hasanbegovic]

What

Commit 1: make the Play upload reach the API correctly.

• Point fastlane supply --metadata_path at play/metadata/android instead of play/metadata in release.yml, play-listing.yml, and the play/README.md example. Supply treats every child of metadata_path as a Play locale, so the old path made it upload a single bogus locale named android (Invalid request from the Play API, first surfaced once the 1.0.1 run got past the disabled-API error).
• Move play/metadata/android/bs/ to play/metadata/unsupported/bs/. Google Play does not offer Bosnian (bs) as a store-listing language, so supply's upload for it is rejected outright. The translated listing content is parked rather than deleted; in-app Bosnian is unaffected.

Commit 2: make sure a release can never ship half-empty again.

• check_play_metadata.py hard-fails when EXPECTED_VERSION_CODE is set and any locale lacks changelogs/<code>.txt; release.yml now exposes the tag-derived versionCode as a job output and passes it to the lint, so a tag without release notes stops before the Play upload. play-listing.yml doesn't set it, so listing-only syncs are unaffected.
• The flatten step (both workflows) now also flattens images/icon/ to Supply's images/icon.png, so the 512x512 store icon uploads automatically once it's committed; previously only featureGraphic/ was flattened and a committed icon would have been silently ignored.
• Renamed the never-shipped 1.0.0 release notes (changelogs/10000.txt) to 10001.txt in all five locales: no 1.0.0 tag exists, so 1.0.1 is the initial public release and the "Initial release." copy is its release copy.
• README: documented the versionCode scheme, the release-notes-before-tagging rule, and the icon/featureGraphic directory convention.

Testing

• Play Listing Sync (validate_only=true, images included): fails on main (android - Invalid request, runs 31900131748 / 31900249999), Successfully validated the upload to Google Play on this branch for all 5 locales (runs 31900400508, 31900845136, the latter with the new flatten + lint in place). Validate-only builds the full edit server-side and discards it; no binary uploaded.
• Lint locally: no env = 5 icon warnings, exit 0; EXPECTED_VERSION_CODE=10001 = exit 0; EXPECTED_VERSION_CODE=10002 = 5 missing-changelog errors, exit 1.
• Flatten loop locally with a simulated images/icon/ PNG: produces featureGraphic.png for all 5 locales plus icon.png where present.

[emir-hasanbegovic]

Added per-locale release notes for the next release as changelogs/10002.txt (assumes the next tag is 1.0.2; if it becomes 1.1.0, git mv them to 10100.txt). Content covers the only user-facing change since 1.0.1: Steam Controller over USB Direct (#154). All five files are 413 to 453 chars, and the lint passes with EXPECTED_VERSION_CODE=10002.