feat(app): directory protocol types, behaviour, relay_discoverable setting

- protocol/directory.rs: DirectoryRequest/Response/ProfileEntry + DIRECTORY_PROTOCOL
- node/behaviour.rs: directory_service field on DuskBehaviour
- node/swarm.rs: outbound directory_service cbor behaviour
- storage/disk.rs: relay_discoverable bool in UserSettings (default true)
- types.ts: relay_discoverable added to UserSettings interface

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

src-tauri/src/node/behaviour.rs

@@ -1,3 +1,4 @@
+use crate::protocol::directory::{DirectoryRequest, DirectoryResponse};
 use crate::protocol::gif::{GifRequest, GifResponse};
 use libp2p::{
     gossipsub, identify, kad, mdns, ping, relay, rendezvous, request_response::cbor,
@@ -15,4 +16,6 @@ pub struct DuskBehaviour {
     pub ping: ping::Behaviour,
     // gif search: sends requests to the relay, receives responses
     pub gif_service: cbor::Behaviour<GifRequest, GifResponse>,
+    // directory search: register/search/remove profiles on the relay
+    pub directory_service: cbor::Behaviour<DirectoryRequest, DirectoryResponse>,
 }

src-tauri/src/node/swarm.rs

@@ -9,6 +9,7 @@ use libp2p::{
 };
 
 use super::behaviour::DuskBehaviour;
+use crate::protocol::directory::{DirectoryRequest, DirectoryResponse, DIRECTORY_PROTOCOL};
 use crate::protocol::gif::{GifRequest, GifResponse, GIF_PROTOCOL};
 
 pub fn build_swarm(
@@ -85,6 +86,12 @@ pub fn build_swarm(
                     request_response::Config::default()
                         .with_request_timeout(Duration::from_secs(15)),
                 ),
+                // directory search via request-response to the relay (outbound only)
+                directory_service: cbor::Behaviour::<DirectoryRequest, DirectoryResponse>::new(
+                    [(DIRECTORY_PROTOCOL, ProtocolSupport::Outbound)],
+                    request_response::Config::default()
+                        .with_request_timeout(Duration::from_secs(15)),
+                ),
             }
         })?
         .with_swarm_config(|cfg| cfg.with_idle_connection_timeout(Duration::from_secs(300)))

src-tauri/src/protocol/directory.rs

@@ -0,0 +1,27 @@
+// directory protocol types for the relay-backed peer discovery service.
+// the client sends DirectoryRequests to the relay and receives DirectoryResponses.
+
+use libp2p::StreamProtocol;
+
+pub const DIRECTORY_PROTOCOL: StreamProtocol =
+    StreamProtocol::new("/dusk/directory/1.0.0");
+
+#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
+pub enum DirectoryRequest {
+    Register { display_name: String },
+    Search { query: String },
+    Remove,
+}
+
+#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
+pub enum DirectoryResponse {
+    Ok,
+    Results(Vec<DirectoryProfileEntry>),
+}
+
+#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
+pub struct DirectoryProfileEntry {
+    pub peer_id: String,
+    pub display_name: String,
+    pub last_seen: u64,
+}

src-tauri/src/protocol/mod.rs

@@ -1,4 +1,5 @@
 pub mod community;
+pub mod directory;
 pub mod gif;
 pub mod identity;
 pub mod messages;

src-tauri/src/storage/disk.rs

@@ -27,8 +27,12 @@ pub struct UserSettings {
     pub font_size: String,
     #[serde(default)]
     pub custom_relay_addr: Option<String>,
+    #[serde(default = "default_true")]
+    pub relay_discoverable: bool,
 }
 
+fn default_true() -> bool { true }
+
 impl Default for UserSettings {
     fn default() -> Self {
         Self {
@@ -43,6 +47,7 @@ impl Default for UserSettings {
             message_display: "cozy".to_string(),
             custom_relay_addr: None,
             font_size: "default".to_string(),
+            relay_discoverable: true,
         }
     }
 }

src/lib/types.ts

@@ -68,6 +68,9 @@ export interface UserSettings {
 
   // network
   custom_relay_addr?: string;
+
+  // discovery
+  relay_discoverable: boolean;
 }
 
 export interface CommunityMeta {