v0.3.0

The whole Chocolate Doom family in one component. Doom and Heretic ship
with their shareware episodes; Hexen and Strife ship as engines for the
hexen.wad and strife1.wad you own, and the demo project shows how.

Added

• Strife. config.game = strife runs Chocolate Strife (engine/patches/0004)
  from the operator's strife1.wad in the gateway's wads folder, with
  voices.wad fetched as a companion when present (else -novoice). No
  free Strife data exists, so the module ships the engine only. Folder
  save slots (strfsav<N>.ssg/), output.gold, output.questFlags and
  Gold/QuestFlags tags. (#7)
• Demo project: Hexen and Strife say NEEDS YOUR WAD instead of SHIPS,
  and their pages open with a three-step how-to (where the data comes from,
  where it goes on the gateway, play). The README has the same guide.
• README pictures for the launcher, Heretic, Hexen, Strife and the how-to
  page, regenerated by SCREENSHOTS=1 npx playwright test screenshots.

Fixed

• A game with no bundled IWAD and none on the gateway (Hexen, Strife) no
  longer preloads a nameless .wad and logs a 404 before reporting that it
  cannot start; the check runs before the engine module is created.