application: channels bounded context

CQRS use cases (create/update/delete/get/list/list_by_owner),
ownership checks, auto-snapshot on config change.
Channel setters added to domain model.

crates/domain/src/models/channel.rs

@@ -194,6 +194,44 @@ impl Channel {
     pub fn updated_at(&self) -> DateTime<Utc> {
         self.updated_at
     }
+
+    // -- Setters --
+
+    /// Update the channel name and touch `updated_at`.
+    pub fn set_name(&mut self, name: impl Into<String>) {
+        self.name = name.into();
+        self.updated_at = Utc::now();
+    }
+
+    /// Update the description and touch `updated_at`.
+    pub fn set_description(&mut self, description: Option<String>) {
+        self.description = description;
+        self.updated_at = Utc::now();
+    }
+
+    /// Update the timezone and touch `updated_at`.
+    pub fn set_timezone(&mut self, timezone: impl Into<String>) {
+        self.timezone = timezone.into();
+        self.updated_at = Utc::now();
+    }
+
+    /// Replace the schedule config and touch `updated_at`.
+    pub fn set_schedule_config(&mut self, config: ScheduleConfig) {
+        self.schedule_config = config;
+        self.updated_at = Utc::now();
+    }
+
+    /// Replace the recycle policy and touch `updated_at`.
+    pub fn set_recycle_policy(&mut self, policy: RecyclePolicy) {
+        self.recycle_policy = policy;
+        self.updated_at = Utc::now();
+    }
+
+    /// Toggle auto-schedule and touch `updated_at`.
+    pub fn set_auto_schedule(&mut self, enabled: bool) {
+        self.auto_schedule = enabled;
+        self.updated_at = Utc::now();
+    }
 }
 
 // ============================================================================