Add lazy P2P demand tracking and need_p2p override (#2003)

- add lazy_p2p so nodes only start background P2P for peers that actually have recent business traffic
- add need_p2p so specific peers can still request eager background P2P even when other nodes enable lazy mode
- cover the new behavior with focused connector/peer-manager tests plus three-node integration tests that verify relay-to-direct route transition

easytier-web/frontend-lib/src/components/Config.vue

@@ -93,10 +93,12 @@ const bool_flags: BoolFlag[] = [
   { field: 'disable_quic_input', help: 'disable_quic_input_help' },
   { field: 'disable_p2p', help: 'disable_p2p_help' },
   { field: 'p2p_only', help: 'p2p_only_help' },
+  { field: 'lazy_p2p', help: 'lazy_p2p_help' },
   { field: 'bind_device', help: 'bind_device_help' },
   { field: 'no_tun', help: 'no_tun_help' },
   { field: 'enable_exit_node', help: 'enable_exit_node_help' },
   { field: 'relay_all_peer_rpc', help: 'relay_all_peer_rpc_help' },
+  { field: 'need_p2p', help: 'need_p2p_help' },
   { field: 'multi_thread', help: 'multi_thread_help' },
   { field: 'proxy_forward_by_system', help: 'proxy_forward_by_system_help' },
   { field: 'disable_encryption', help: 'disable_encryption_help' },

easytier-web/frontend-lib/src/locales/cn.yaml

@@ -113,6 +113,9 @@ disable_p2p_help: 禁用 P2P 模式，所有流量通过手动指定的服务器
 p2p_only: 仅 P2P
 p2p_only_help: 仅与已经建立P2P连接的对等节点通信，不通过其他节点中转。
 
+lazy_p2p: 延迟 P2P
+lazy_p2p_help: 仅在实际流量需要某个对等节点时才尝试建立 P2P。开启 need-p2p 的节点仍会被主动连接。
+
 bind_device: 仅使用物理网卡
 bind_device_help: 仅使用物理网卡，避免 EasyTier 通过其他虚拟网建立连接。
 
@@ -127,6 +130,9 @@ relay_all_peer_rpc_help: |
   允许转发所有对等节点的RPC数据包，即使对等节点不在转发网络白名单中。
   这可以帮助白名单外网络中的对等节点建立P2P连接。
 
+need_p2p: 需要 P2P
+need_p2p_help: 即使其他节点启用了 lazy p2p，也要求它们主动与当前节点建立 P2P 连接。
+
 multi_thread: 启用多线程
 multi_thread_help: 使用多线程运行时
 

easytier-web/frontend-lib/src/locales/en.yaml

@@ -112,6 +112,9 @@ disable_p2p_help: Disable P2P mode; route all traffic through a manually specifi
 p2p_only: P2P Only
 p2p_only_help: Only communicate with peers that have already established P2P connections, do not relay through other nodes.
 
+lazy_p2p: Lazy P2P
+lazy_p2p_help: Only try to establish P2P when traffic actually targets a peer. Peers with need-p2p enabled are still connected proactively.
+
 bind_device: Bind to Physical Device Only
 bind_device_help: Use only the physical network interface to prevent EasyTier from connecting via virtual networks.
 
@@ -126,6 +129,9 @@ relay_all_peer_rpc_help: |
   Relay all peer rpc packets, even if the peer is not in the relay network whitelist.
   This can help peers not in relay network whitelist to establish p2p connection.
 
+need_p2p: Need P2P
+need_p2p_help: Ask other peers to proactively establish P2P connections to this node even when they enable lazy P2P.
+
 multi_thread: Multi Thread
 multi_thread_help: Use multi-thread runtime
 

easytier-web/frontend-lib/src/types/network.ts

@@ -53,10 +53,12 @@ export interface NetworkConfig {
   disable_quic_input?: boolean
   disable_p2p?: boolean
   p2p_only?: boolean
+  lazy_p2p?: boolean
   bind_device?: boolean
   no_tun?: boolean
   enable_exit_node?: boolean
   relay_all_peer_rpc?: boolean
+  need_p2p?: boolean
   multi_thread?: boolean
   proxy_forward_by_system?: boolean
   disable_encryption?: boolean
@@ -125,10 +127,12 @@ export function DEFAULT_NETWORK_CONFIG(): NetworkConfig {
     disable_quic_input: false,
     disable_p2p: false,
     p2p_only: false,
+    lazy_p2p: false,
     bind_device: true,
     no_tun: false,
     enable_exit_node: false,
     relay_all_peer_rpc: false,
+    need_p2p: false,
     multi_thread: true,
     proxy_forward_by_system: false,
     disable_encryption: false,