Introduce stable server IDs for subscription state

src/shared/contracts/state.js

@@ -1,4 +1,5 @@
 import { normalizeRouteRules } from '../routingRules.js';
+import { normalizeServers, resolveServerId } from '../serverIdentity.js';
 
 const MODES = new Set(['client', 'gateway']);
 const CONNECTION_STATES = new Set(['running', 'stopped']);
@@ -12,13 +13,21 @@ const dateOrNull = (value) => (
 
 export function normalizeStoredState(value) {
   const state = value && typeof value === 'object' && !Array.isArray(value) ? value : {};
-  const selectedTag = text(state.selectedTag);
+  const servers = normalizeServers(state.servers);
+  const selectedServerId = resolveServerId(servers, state.selectedServerId, state.selectedTag);
+  const appliedServerId = Object.hasOwn(state, 'appliedServerId')
+    ? resolveServerId(servers, state.appliedServerId)
+    : resolveServerId(servers, '', state.appliedTag || state.selectedTag);
+  const selectedServer = servers.find((server) => server.id === selectedServerId);
+  const appliedServer = servers.find((server) => server.id === appliedServerId);
   return {
     ...state,
     revision: Number.isSafeInteger(state.revision) && state.revision >= 0 ? state.revision : 0,
-    selectedTag,
-    appliedTag: Object.hasOwn(state, 'appliedTag') ? text(state.appliedTag) : selectedTag,
-    servers: Array.isArray(state.servers) ? state.servers : [],
+    selectedServerId,
+    appliedServerId,
+    selectedTag: selectedServer?.label || '',
+    appliedTag: appliedServer?.label || '',
+    servers,
     routeRules: normalizeRouteRules(state.routeRules),
     appliedRouteRules: normalizeRouteRules(state.appliedRouteRules),
     routeRulesRevision: Number.isSafeInteger(state.routeRulesRevision) && state.routeRulesRevision >= 0
@@ -43,22 +52,7 @@ export function createStateSnapshot({
   const desired = CONNECTION_STATES.has(stored.connectionDesired)
     ? stored.connectionDesired
     : configExists ? 'running' : 'stopped';
-  const servers = stored.servers.map((server) => {
-    const tag = text(server.tag);
-    return {
-      ...server,
-      id: tag,
-      label: tag,
-      host: text(server.server),
-      port: Number(server.server_port) || 0,
-      protocol: text(server.type),
-      // v0 compatibility: the current UI and integrations still read these aliases.
-      tag,
-      server: text(server.server),
-      server_port: Number(server.server_port) || 0,
-      type: text(server.type),
-    };
-  });
+  const servers = stored.servers;
   const routeMode = mode === 'client' ? gatewayAuto?.mode || 'local-vpn' : 'gateway-transparent';
   const activeLocalRules = runtime?.running ? stored.appliedRouteRules : [];
 
@@ -74,8 +68,8 @@ export function createStateSnapshot({
       userInfo: stored.userInfo && typeof stored.userInfo === 'object' ? stored.userInfo : {},
     },
     selection: {
-      desiredServerId: stored.selectedTag,
-      appliedServerId: stored.appliedTag,
+      desiredServerId: stored.selectedServerId,
+      appliedServerId: stored.appliedServerId,
     },
     connection: {
       desired,
@@ -120,7 +114,7 @@ export function withStateV0Compatibility(snapshot, {
     singboxStartedAt: snapshot.connection.startedAt,
     subscriptionHost: snapshot.subscription.host,
     hasSubscription: snapshot.subscription.status === 'ready',
-    selectedTag: snapshot.selection.desiredServerId,
+    selectedTag: stored.selectedTag,
     userInfo: snapshot.subscription.userInfo,
     fetchedAt: snapshot.subscription.fetchedAt,
     gatewayAuto: snapshot.mode === 'client' ? {