feat(swarm): Add direct swarm interaction delivery for likes, reposts, and unreosts

- Add swarm post handling to like endpoint with direct delivery to origin node
- Add swarm post handling to repost endpoint with direct delivery to origin node
- Add new unrepost endpoint for removing reposts from swarm posts
- Implement deliverSwarmUnrepost function in interactions library
- Extract swarm domain and post ID validation for all interaction types
- Return appropriate error responses for invalid swarm post IDs
- Log successful swarm interaction deliveries for debugging
- Improve separation between local post and swarm post handling logic
- Enable federated users to interact with remote swarm posts directly without local caching

src/lib/swarm/interactions.ts

@@ -110,6 +110,16 @@ export interface SwarmUnfollowPayload {
   };
 }
 
+export interface SwarmUnrepostPayload {
+  postId: string;
+  unrepost: {
+    actorHandle: string;
+    actorNodeDomain: string;
+    interactionId: string;
+    timestamp: string;
+  };
+}
+
 export interface SwarmMentionPayload {
   mentionedHandle: string;
   mention: {
@@ -219,6 +229,16 @@ export async function deliverSwarmUnfollow(
   return deliverSwarmInteraction(targetDomain, '/api/swarm/interactions/unfollow', payload);
 }
 
+/**
+ * Deliver an unrepost to a swarm node
+ */
+export async function deliverSwarmUnrepost(
+  targetDomain: string,
+  payload: SwarmUnrepostPayload
+): Promise<SwarmInteractionResponse> {
+  return deliverSwarmInteraction(targetDomain, '/api/swarm/interactions/unrepost', payload);
+}
+
 /**
  * Deliver a mention notification to a swarm node
  */