huskies: merge 1163 story Replace perm_rx lock-as-presence-signal with a permission router

server/src/service/gateway/io.rs

@@ -507,11 +507,7 @@ pub fn spawn_gateway_bot(
     gateway_projects_store: std::sync::Arc<tokio::sync::RwLock<BTreeMap<String, ProjectEntry>>>,
     port: u16,
     gateway_event_tx: Option<tokio::sync::broadcast::Sender<super::GatewayStatusEvent>>,
-    perm_rx: std::sync::Arc<
-        tokio::sync::Mutex<
-            tokio::sync::mpsc::UnboundedReceiver<crate::http::context::PermissionForward>,
-        >,
-    >,
+    permission_registry: std::sync::Arc<crate::service::permission_router::ResponderRegistry>,
 ) -> (
     Option<tokio::task::AbortHandle>,
     tokio::sync::watch::Sender<Option<crate::rebuild::ShutdownReason>>,
@@ -550,10 +546,8 @@ pub fn spawn_gateway_bot(
                 .map(|c| c.ambient_rooms.iter().cloned().collect())
                 .unwrap_or_default(),
         )),
-        perm_rx,
-        pending_perm_replies: std::sync::Arc::new(tokio::sync::Mutex::new(
-            std::collections::HashMap::new(),
-        )),
+        permission_registry,
+        pending_perm_replies: crate::service::permission_router::PendingPermReplies::new(),
         permission_timeout_secs: bot_cfg
             .as_ref()
             .map(|c| c.permission_timeout_secs)
@@ -599,9 +593,7 @@ mod tests {
         let active = std::sync::Arc::new(tokio::sync::RwLock::new("proj".to_string()));
         let (event_tx, _) = tokio::sync::broadcast::channel(4);
 
-        let (_perm_tx, perm_rx) =
-            tokio::sync::mpsc::unbounded_channel::<crate::http::context::PermissionForward>();
-        let perm_rx = std::sync::Arc::new(tokio::sync::Mutex::new(perm_rx));
+        let permission_registry = crate::service::permission_router::ResponderRegistry::new();
         let projects_store =
             std::sync::Arc::new(tokio::sync::RwLock::new(std::collections::BTreeMap::new()));
         let (handle, shutdown_tx) = spawn_gateway_bot(
@@ -610,7 +602,7 @@ mod tests {
             projects_store,
             3001,
             Some(event_tx),
-            perm_rx,
+            permission_registry,
         );
 
         // No bot.toml in tmp → no abort handle spawned.

server/src/service/gateway/mod.rs

@@ -224,11 +224,14 @@ pub struct GatewayState {
     /// received from connected sleds into the gateway's Matrix bot permission
     /// pipeline.
     pub perm_tx: mpsc::UnboundedSender<PermissionForward>,
-    /// Receiver end of the gateway's permission channel (shared with the Matrix bot).
+    /// Registry of tasks registered to receive forwarded permission requests
+    /// (shared with the gateway's embedded Matrix bot).
     ///
-    /// The Matrix bot's `permission_listener` holds this locked for its lifetime;
-    /// the sled-uplink WS handler sends requests via `perm_tx`.
-    pub perm_rx: Arc<TokioMutex<mpsc::UnboundedReceiver<PermissionForward>>>,
+    /// The Matrix bot's `permission_listener` registers with this for its
+    /// lifetime; the sled-uplink WS handler sends requests via `perm_tx`,
+    /// which the router task (spawned in [`GatewayState::new`]) dispatches
+    /// into this registry.
+    pub permission_registry: Arc<crate::service::permission_router::ResponderRegistry>,
     /// Reversed sled-token map: token → project_name (sled_id).
     ///
     /// Built at startup from both [`GatewayConfig::sled_tokens`] AND the
@@ -261,6 +264,16 @@ impl GatewayState {
             .unwrap_or(first_from_config);
         let (event_tx, _) = tokio::sync::broadcast::channel(EVENT_CHANNEL_CAPACITY);
         let (perm_tx, perm_rx) = mpsc::unbounded_channel::<PermissionForward>();
+        let permission_registry = crate::service::permission_router::ResponderRegistry::new();
+        // `GatewayState::new` is also called from plain `#[test]` fns with no
+        // tokio runtime; skip spawning when there's no reactor to spawn onto
+        // since those tests never exercise the permission plumbing.
+        if tokio::runtime::Handle::try_current().is_ok() {
+            crate::service::permission_router::spawn_permission_router(
+                perm_rx,
+                Arc::clone(&permission_registry),
+            );
+        }
 
         // Build token→project_name map from two sources:
         // 1. Legacy top-level [sled_tokens] section (sled_id → token, reversed)
@@ -287,7 +300,7 @@ impl GatewayState {
             bot_shutdown_tx: Arc::new(TokioMutex::new(None)),
             event_tx,
             perm_tx,
-            perm_rx: Arc::new(TokioMutex::new(perm_rx)),
+            permission_registry,
             sled_tokens,
             sled_connections: Arc::new(RwLock::new(HashMap::new())),
         })
@@ -683,7 +696,7 @@ pub async fn save_bot_config_and_restart(state: &GatewayState, content: &str) ->
             Arc::clone(&state.projects),
             state.port,
             Some(state.event_tx.clone()),
-            Arc::clone(&state.perm_rx),
+            Arc::clone(&state.permission_registry),
         );
         *handle = new_handle;
         *state.bot_shutdown_tx.lock().await = Some(new_shutdown_tx);