feat(settings): Settings1 стаб + атомарный стор + seed дефолтов

Store (load_or_seed/get/set/reset/list, durable-write) + SettingsService #[interface] + bin.
v0: строковые значения (variant на проводе), сам сеет дефолты.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Signed-off-by: Alexander <akotenev2003@gmail.com>

Cargo.toml

@@ -7,6 +7,7 @@ members = [
     "crates/shturman-ipc",
     "crates/shturman-sdk",
     "crates/core/shturman-firstboot",
+    "crates/core/shturman-settings",
 ]
 
 [workspace.package]