docs: correct stale module claims and document amlich edge cases

README omitted /lol_subscribe and /lol_unsubscribe, called gold opt-in
though an empty MODULES loads every catalog module, and left out both
the amlich 1800-2199 bound and the lol module's PandaScore token. The
gold factory comment repeated the same opt-in claim.

Promote the lunar algorithm decision record and known-issue list into
docs/ so they survive cleanups of plans/.

internal/modules/gold/gold.go

@@ -4,8 +4,8 @@ import (
 	"github.com/tiennm99/miti99bot/internal/modules"
 )
 
-// New is the gold paper-trading module factory. It is opt-in through MODULES
-// and keeps its portfolio state separate from the stock module.
+// New is the gold paper-trading module factory. It keeps its portfolio state
+// separate from the stock module.
 func New(deps modules.Deps) modules.Module {
 	s := newState(deps.Store)
 	return modules.Module{