v0.2.1 - Early Weapon does what it says, a new easy tier, and a yaml you can read

Matched pair: install the plugin zip AND regenerate with this cw4.apworld. The plugin and the apworld share a version number and must match.

Requires Archipelago 0.6.7 or newer.

Existing yamls keep working, and a yaml that names no new setting means what it meant before. Seeds do change: a solo or all-Creeper-World-4 seed number generates a different layout than it did in v0.2.0, because the early weapon is now actually placed early.

• Fixed: early_weapon did nothing when every player was Creeper World 4,
  solo included, from v0.1.3 to v0.2.0. The option asks Archipelago to place
  the chosen weapon - and a second mission unlock - in the checks you can reach
  with nothing. But on those seeds the world places its own progression first,
  so it can retry where Archipelago's fill would give up, and it took both items
  out of the pool before Archipelago looked for them. Nothing warned. Measured
  over 10,000 solo seeds: the chosen weapon came first on 38 percent of them,
  the early unlock on 11. The world now places both itself, first.
• Fixed: in a multiworld with other games, a narrow opening asked for
  nothing early. Casual logic at 2 starters, or a SPAN draw with only one
  check open at the start, stood its requests down for a bootstrap that only
  runs when every player is Creeper World 4. 13 to 48 percent of CW4 players in
  those multiworlds got neither. They now get the requests. When only one check
  is open, the mission unlock gets it.
• Measured, not assumed. A new tool, tools/audit/earlysweep.py, generates
  through the same path a player's seed takes and checks where the items
  actually LAND. 10,000 seeds in each of seven shapes - solo, two and four CW4
  players, and CW4 beside ChecksFinder, VVVVVV, Meritous and Timespinner: 0
  generation failures, 0 unreachable or unbeatable seeds, and the weapon and
  the unlock early in every one that asked. As a side effect the world's own
  fill now has to retry 7 to 20 times less often.
• Placements change. A solo or all-CW4 seed number generates a different
  layout than it did in v0.2.0, and so does a mixed multiworld whose CW4
  opening is narrow; any other mixed multiworld is unchanged.
  tools/span-off-parity.sh and tools/refactor-parity.sh report the
  difference, by design.
• The yaml is short now. Creeper World 4.yaml used to be the template
  Archipelago generates, 635 lines of its own boilerplate and of notes written
  for whoever maintains the world. It is now written by hand, 120 lines: each
  option at its default with a line or two on what it does and the values it
  takes, in the order of the options page - Archipelago's own progression
  balancing and accessibility first, as in its official template, then the
  goal and logic, traps, energy upgrades and ERNs. The descriptions on the options page are
  rewritten for players as well; the design notes moved into the code.
• New: logic_difficulty: easy. Casual asks for a Sniper OR a Missile
  Launcher from We Were Never Alone (mission 6) onward. Easy asks the same until
  The Experiment (mission 13) - the designer's "small spike in map difficulty",
  where the worksheet calls snipers, missiles and a cannon over a mortar all
  worth having - and from there all four of Sniper, Missile Launcher, Cannon
  and Mortar. Like casual it counts by story number, so every SPAN map gets all
  four, and it gates every check on those missions except the free caches. The
  in-game tracker needs no update: it reads the requirements from the seed, so
  a check missing one of the four shows yellow. Measured over 21,000 seeds in
  seven multiworld shapes - solo, two and four CW4 players, and CW4 beside one
  to four other games: 0 generation failures, and the early weapon still lands
  early.
• Four options that do nothing are hidden from the options page and the
  yaml: trap_weight_emitter_overdrive and the three filler_*_weight
  options. A yaml that still names them generates as before.