refactor(workspace): enforce layered crate boundaries

crates/aether-task/core/src/definition.rs

@@ -0,0 +1,62 @@
+use serde::{Deserialize, Serialize};
+
+use crate::RetryPolicy;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+pub enum TaskKind {
+    Scheduled,
+    Daemon,
+    OnDemand,
+    FireAndForget,
+}
+
+impl TaskKind {
+    pub const fn as_str(self) -> &'static str {
+        match self {
+            Self::Scheduled => "scheduled",
+            Self::Daemon => "daemon",
+            Self::OnDemand => "on_demand",
+            Self::FireAndForget => "fire_and_forget",
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+pub struct TaskDefinition {
+    pub key: &'static str,
+    pub kind: TaskKind,
+    pub trigger: &'static str,
+    pub singleton: bool,
+    pub persist_history: bool,
+    pub retry_policy: RetryPolicy,
+}
+
+impl TaskDefinition {
+    pub const fn new(
+        key: &'static str,
+        kind: TaskKind,
+        trigger: &'static str,
+        singleton: bool,
+        persist_history: bool,
+        retry_policy: RetryPolicy,
+    ) -> Self {
+        Self {
+            key,
+            kind,
+            trigger,
+            singleton,
+            persist_history,
+            retry_policy,
+        }
+    }
+
+    pub const fn singleton(
+        key: &'static str,
+        kind: TaskKind,
+        trigger: &'static str,
+        persist_history: bool,
+        retry_policy: RetryPolicy,
+    ) -> Self {
+        Self::new(key, kind, trigger, true, persist_history, retry_policy)
+    }
+}