docs(gui): mend the desktop crate's intra-doc links

openlogi-desktop sits outside the rustdoc CI job, so its broken intra-doc links go unnoticed; `cargo doc -p openlogi-desktop --document-private-items` under -D warnings reported twelve. Two were left by yesterday's splits — [`key_points`] became ambiguous with the module of the same name, and the import pruning took away the LABEL_H a doc link relied on — and ten were older: renamed methods (AppState::current_device → current_record, battery_context → Self::status), a cfg-gated variant, a test function, a macro_rules! macro, and items no longer in scope.

Links now carry the path they need or become plain code spans where rustdoc cannot link (a variant built only off macOS, a macro_rules! macro, a test). The crate documents clean under -D warnings.