Add generic trading helpers and reduce public API tiers (#58)

* feat: add generic trading helpers and API tiers

* Bump version to v0.9.3

* fix: require symbol digits for trailing stops

* fix: allow side-specific trailing stop ticks

* test: enforce complete public export tiers

* docs: align public contract tiers

* refactor: remove legacy public supports

uv.lock

@@ -487,7 +487,7 @@ wheels = [
 
 [[package]]
 name = "mt5cli"
-version = "0.9.2"
+version = "0.9.3"
 source = { editable = "." }
 dependencies = [
     { name = "click" },