feat(#1102): add list_invites and join_room to matrix MCP

hive-matrix-mcp/src/protocol.rs

@@ -68,6 +68,19 @@ pub enum DaemonRequest {
     #[serde(rename = "read_room")]
     ReadRoom { room: String, limit: Option<usize> },
 
+    /// List rooms this agent has been invited to but not yet joined.
+    /// Returns each room's id, canonical alias (when present), and
+    /// display name.
+    #[serde(rename = "list_invites")]
+    ListInvites,
+
+    /// Join a room by id (`!abc:server`) or alias (`#name:server`).
+    /// Accepts a pending invite if one exists; also joins public rooms
+    /// the agent hasn't been explicitly invited to. After joining the
+    /// room will appear in `list_rooms`.
+    #[serde(rename = "join_room")]
+    JoinRoom { room: String },
+
     /// Liveness probe — fast "are you up?" round-trip that doesn't
     /// touch matrix-sdk. Not used by the in-tree stdio MCP bridge
     /// (which surfaces a daemon-down condition as a normal tool-call