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.base/index.ludic

@@ -1,6 +1,6 @@
 # ludic.base - what a mechanic may use and nothing else: the frame it is handed, the phases
 # that order it, queues for the facts it reports, its own dice, its save section, its system
-module ludic_base
+module ludic_base uses
 numbers float
 import "tick.ludic"
 import "queue.ludic"