refactor(packages): the mechanic packages use ludic_base only, and ask through ports

ludic.clock, .effects, .inventory, .wallet, .weather and .tracks say
'uses ludic_base' (ludic.base uses nothing). ClockWorld, PackRules,
WeatherWorld and TracksWorld are export ports whose defaults are the old
fallbacks; clock_bind, inv_bind, weather_bind and tracks_bind are gone,
and the tests bind their fakes. The base README's toy does the same.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/ludic.tracks/index.ludic

@@ -1,6 +1,6 @@
 # ludic.tracks - a ring of prints per kind, each remembering who left it, which way it went and
 # when; reading one is a fact on a queue, and the game draws them through a hook
-module ludic_tracks
+module ludic_tracks uses ludic_base
 numbers float
 import "ludic.base"
 import "state.ludic"