Release launchers when a game is added, not just on a tag

[vadi2]

Adding a game to GameList.txt never produced a launcher for it. The daily sync-games PR merges to development, the compile job builds every game's installer, and then the artifacts expire in 90 days - the release job was gated on startsWith(github.ref, 'refs/tags/'), so nothing reached a GitHub Release until someone hand-cut a tag.

• New check-new-games job compares GameList.txt at HEAD against GameList.txt at the newest v* tag. Comparing against the last release rather than the previous commit means a push whose release failed still gets retried by the next one.
• When games were added it bumps the patch component (v1.3.0 -> v1.3.1) and lets release run off the development push. softprops/action-gh-release creates the tag itself, pinned to github.sha.
• No release loop: tags created with GITHUB_TOKEN don't trigger workflows. Removals don't trigger a release, and neither do dependabot bumps.

Merging this cuts v1.3.1, which backfills the 8 games that have had no launcher since v1.3.0 (2026-01-07): Beyond the Void MUD, Dragonfire MUD, Federation 2 Community Edition, Icesus, mg.mud.de, PhoenixMUD, Pku XKX MUD, Starmourn.

Test case: ran the detection logic against the repo's real history - it picks v1.3.0 as the baseline, reports exactly those 8 games, and computes v1.3.1; the no-new-games path, the version bump on malformed tags, and the abort-on-missing-GameList path all behave.

Assisted-by: Claude:claude-opus-5