refactor(lib_commands): drop super::* + glob in app_api + lib_commands root

Hotspot G final slice — replace cascade-imports in app_api/{core,
analysis,integration,remote,platform}.rs with explicit per-symbol
imports, and convert app_api/mod.rs from broad `pub(crate) use foo::*`
to a per-command list of every Tauri handler.

The remaining glob re-exports live only in lib_commands/mod.rs itself
— and those are deliberate: they flatten the explicitly-listed Tauri
commands one more level so lib.rs's `use lib_commands::*` keeps the
invoke_handler shape unchanged. Each level above is now explicit.

file_transfer.rs's `super::subsonic_wire_user_agent()` becomes
`crate::subsonic_wire_user_agent()` since the lib_commands cascade
no longer pulls lib.rs symbols into super scope.

`grep -rn 'use super::\*' src/lib_commands/` returns zero hits.
Behaviour-preserving.

src-tauri/src/lib_commands/mod.rs

@@ -1,11 +1,12 @@
-use super::*;
-
-mod app_api;
-mod cache;
-mod file_transfer;
-mod sync;
-mod ui;
+pub(crate) mod app_api;
+pub(crate) mod cache;
+pub(crate) mod file_transfer;
+pub(crate) mod sync;
+pub(crate) mod ui;
 
+// Each subdirectory re-exports its Tauri commands explicitly. Flatten one
+// more level here so `lib.rs`'s `use lib_commands::*;` lands every
+// invoke-handler-registered name at lib.rs scope.
 pub(crate) use app_api::*;
 pub(crate) use cache::*;
 pub(crate) use sync::*;