Refactor application structure and simplify implementation

src-tauri/src/clock.rs

@@ -0,0 +1,19 @@
+//! Small injectable time boundary for deterministic activity records.
+
+use std::time::{SystemTime, UNIX_EPOCH};
+
+pub trait Clock {
+    fn now(&self) -> String;
+}
+
+pub struct SystemClock;
+
+impl Clock for SystemClock {
+    fn now(&self) -> String {
+        let seconds = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .map(|duration| duration.as_secs())
+            .unwrap_or(0);
+        format!("unix:{seconds}")
+    }
+}