feat(discovery-core): add outgoing state sync orchestrator

crates/discovery-core/src/discovery/cursor.rs

@@ -71,8 +71,7 @@ pub struct ChannelCursor {
     // TODO: Consider encrypting/masking channel_key in the serialized cursor
     // to avoid exposing it in plaintext (sensitive value).
     /// The channel key for this channel.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub channel_key: Option<Felt>,
+    pub channel_key: Felt,
 
     /// All subchannels have been enumerated. Set by the discovery service
     /// once the sentinel subchannel is reached. When `true`, no further

crates/discovery-core/src/discovery/incoming_channels.rs

@@ -224,7 +224,7 @@ pub async fn discover_incoming_channels_paginated<S: IViews>(
             .channels
             .entry(channel.sender_addr)
             .or_insert(ChannelCursor {
-                channel_key: Some(channel.channel_key),
+                channel_key: channel.channel_key,
                 subchannel_discovery_complete: false,
                 last_subchannel_index: None,
                 subchannels: Default::default(),
@@ -467,8 +467,9 @@ mod tests {
 
         let sender_addr = channels[0].sender_addr;
         assert!(cursor.channels.contains_key(&sender_addr));
-        assert!(
-            cursor.channels[&sender_addr].channel_key.is_some(),
+        assert_ne!(
+            cursor.channels[&sender_addr].channel_key,
+            Felt::ZERO,
             "channel_key should be set for incoming channels"
         );
     }

crates/discovery-core/src/discovery/outgoing_channels.rs

@@ -124,7 +124,7 @@ pub async fn discover_outgoing_channels_paginated<S: IViews>(
             .channels
             .entry(channel.recipient_addr)
             .or_insert_with(|| ChannelCursor {
-                channel_key: Some(channel.channel_key),
+                channel_key: channel.channel_key,
                 subchannel_discovery_complete: false,
                 last_subchannel_index: None,
                 subchannels: HashMap::new(),

crates/discovery-core/src/discovery/subchannels.rs

@@ -328,7 +328,7 @@ mod tests {
         .unwrap();
 
         let mut cursor = ChannelCursor {
-            channel_key: Some(channel_key),
+            channel_key,
             subchannel_discovery_complete: false,
             last_subchannel_index: None,
             subchannels: HashMap::new(),
@@ -367,7 +367,7 @@ mod tests {
         .unwrap();
 
         let mut cursor = ChannelCursor {
-            channel_key: Some(channel_key),
+            channel_key,
             subchannel_discovery_complete: false,
             last_subchannel_index: None,
             subchannels: HashMap::new(),
@@ -409,7 +409,7 @@ mod tests {
 
         // Fresh cursor: empty map + no total → should discover subchannels
         let mut fresh = ChannelCursor {
-            channel_key: Some(channel_key),
+            channel_key,
             subchannel_discovery_complete: false,
             last_subchannel_index: None,
             subchannels: HashMap::new(),
@@ -424,7 +424,7 @@ mod tests {
         // Fully enumerated cursor: empty map + skip=true → should skip entirely
         // (simulates state after all notes processed and entries pruned)
         let mut done = ChannelCursor {
-            channel_key: Some(channel_key),
+            channel_key,
             subchannel_discovery_complete: true,
             last_subchannel_index: Some(0),
             subchannels: HashMap::new(),
@@ -484,7 +484,7 @@ mod tests {
 
         // Pre-fill cursor to capacity (1 entry, max = 1).
         let mut cursor = ChannelCursor {
-            channel_key: Some(channel_key),
+            channel_key,
             subchannel_discovery_complete: false,
             last_subchannel_index: None,
             subchannels: HashMap::from([(Felt::from(0xabc), Default::default())]),
@@ -519,7 +519,7 @@ mod tests {
 
         // 1 existing entry + max_cursor_subchannels=2 → 1 slot available.
         let mut cursor = ChannelCursor {
-            channel_key: Some(channel_key),
+            channel_key,
             subchannel_discovery_complete: false,
             last_subchannel_index: None,
             subchannels: HashMap::from([(Felt::from(0xabc), Default::default())]),

crates/discovery-core/src/sync/incoming_state.rs

@@ -171,9 +171,7 @@ async fn process_channel<S: IViews>(
     max_cursor_subchannels: usize,
     budget: &IoBudget,
 ) -> Result<ProcessChannelResult, DiscoveryError> {
-    let channel_key = cursor.channel_key.ok_or_else(|| {
-        DiscoveryError::InvalidCursor("channel_key is required for incoming channel".into())
-    })?;
+    let channel_key = cursor.channel_key;
 
     discover_subchannels_paginated(
         pool,

crates/discovery-core/src/sync/mod.rs

@@ -3,3 +3,4 @@
 //! Composes discovery primitives into complete sync workflows.
 
 pub mod incoming_state;
+pub mod outgoing_state;