fix(strategies): mute prefix color in show output

Wrap the ├─/└─ prefix with fmt.muted / fmt.reset so the tree
guides are visually de-emphasised relative to the key names.

Author: ocots

src/Strategies/contract/abstract_strategy.jl

@@ -506,7 +506,9 @@ function Base.show(io::IO, ::MIME"text/plain", strategy::T) where {T<:AbstractSt
         prefix = is_last ? "└─ " : "├─ "
         println(
             io,
+            fmt.muted,
             prefix,
+            fmt.reset,
             fmt.name,
             key,
             fmt.reset,