- ITwinCATClient.BrowseSymbolsAsync XML doc updated: states the implementation now
expands struct/UDT/FB symbols into atomic member leaves via TwinCATSymbolExpander;
callers receive only atomic/array leaves with full InstancePaths, never struct containers.
- AdsSymbolNode: cache IsStruct, Mapped, Children, ReadOnly as readonly fields computed
once in the ctor so repeated property access during recursive expansion doesn't
re-materialize or re-invoke MapSymbolType/IsSymbolWritable.
- BrowseSymbolsAsync: add operator-gated live risk note next to SymbolsLoadMode.Flat
warning that a real TC3 target may not populate SubSymbols in Flat mode, with
guidance to switch to VirtualTree if members don't surface — do not change mode now.
- TwinCATSymbolExpanderTests: simplify confusing `new string('.', 0)` no-op to `""`.
Joseph Doherty
fdd6b332fe