diff --git a/apps/desktop/src/app/gateway/hooks/gateway-hmr-survivor.ts b/apps/desktop/src/app/gateway/hooks/gateway-hmr-survivor.ts
index dec9f4d1ab74..c627b9390590 100644
--- a/apps/desktop/src/app/gateway/hooks/gateway-hmr-survivor.ts
+++ b/apps/desktop/src/app/gateway/hooks/gateway-hmr-survivor.ts
@@ -24,11 +24,6 @@ function slot(): SurvivorGlobal {
   return globalThis as unknown as SurvivorGlobal
 }
 
-/** True only in a dev server with HMR wired up. Production strips this. */
-export function hmrActive(): boolean {
-  return Boolean(import.meta.hot)
-}
-
 /** Park the live gateway so the next module instance can re-adopt it. */
 export function stashGatewaySurvivor(survivor: GatewaySurvivor): void {
   slot()[SURVIVOR_KEY] = survivor
diff --git a/apps/desktop/src/app/gateway/hooks/use-gateway-boot.ts b/apps/desktop/src/app/gateway/hooks/use-gateway-boot.ts
index 09efb2568753..f02ee69f5e6d 100644
--- a/apps/desktop/src/app/gateway/hooks/use-gateway-boot.ts
+++ b/apps/desktop/src/app/gateway/hooks/use-gateway-boot.ts
@@ -40,7 +40,7 @@ import {
 import { $attentionSessionIds, $workingSessionIds, resetTileRuntimeBindings } from '@/store/session-states'
 import type { RpcEvent } from '@/types/hermes'
 
-import { hmrActive, stashGatewaySurvivor, survivorIsStale, takeGatewaySurvivor } from './gateway-hmr-survivor'
+import { stashGatewaySurvivor, survivorIsStale, takeGatewaySurvivor } from './gateway-hmr-survivor'
 
 // After this many consecutive failed reconnects (≈45s with the 1→15s backoff)
 // raise a recoverable boot error. Otherwise a dropped remote gateway loops the
@@ -342,9 +342,10 @@ export function useGatewayBoot({
     // HMR adoption: in a dev hot update, the previous effect instance parked its
     // still-open socket instead of closing it (see the cleanup below). Re-adopt
     // it so an edit doesn't drop the live agent session. A stale (closed) parked
-    // socket is discarded and we boot fresh. No-op in production (survivor is
-    // always null — the stash path is gated on import.meta.hot).
-    const survivor = takeGatewaySurvivor()
+    // socket is discarded and we boot fresh. No-op in production: import.meta.hot
+    // is undefined there, so this folds to `null` and the whole survivor module
+    // dead-code-eliminates out of the bundle.
+    const survivor = import.meta.hot ? takeGatewaySurvivor() : null
     const adoptedFromHmr = Boolean(survivor && !survivorIsStale(survivor))
 
     if (survivor && !adoptedFromHmr) {
@@ -595,7 +596,7 @@ export function useGatewayBoot({
       // gateway store (HMR-stable module state), so they survive untouched.
       // Production: import.meta.hot is undefined, so this branch never runs and
       // the original destructive teardown below is byte-for-byte preserved.
-      if (hmrActive() && gateway.connectionState === 'open') {
+      if (import.meta.hot && gateway.connectionState === 'open') {
         stashGatewaySurvivor({
           gateway,
           profile: survivor?.profile ?? $activeGatewayProfile.get(),
diff --git a/apps/desktop/src/store/gateway.ts b/apps/desktop/src/store/gateway.ts
index 5027273f86eb..61b6f46abcc7 100644
--- a/apps/desktop/src/store/gateway.ts
+++ b/apps/desktop/src/store/gateway.ts
@@ -60,24 +60,36 @@ interface GatewayRegistryState {
 
 const STATE_KEY = Symbol.for('hermes.desktop.gatewayRegistryState')
 
-function gatewayState(): GatewayRegistryState {
-  const store = globalThis as unknown as { [STATE_KEY]?: GatewayRegistryState }
+function createRegistryState(): GatewayRegistryState {
+  return {
+    config: null,
+    primaryGateway: null,
+    primaryProfile: 'default',
+    activeKey: 'default',
+    secondaries: new Map<string, Secondary>(),
+    // The active gateway instance, exposed for inline message-stream
+    // components (inline ClarifyTool, model overlays) that call gateway
+    // methods without the instance threaded down through props.
+    $gateway: atom<HermesGateway | null>(null)
+  }
+}
 
-  if (!store[STATE_KEY]) {
-    store[STATE_KEY] = {
-      config: null,
-      primaryGateway: null,
-      primaryProfile: 'default',
-      activeKey: 'default',
-      secondaries: new Map<string, Secondary>(),
-      // The active gateway instance, exposed for inline message-stream
-      // components (inline ClarifyTool, model overlays) that call gateway
-      // methods without the instance threaded down through props.
-      $gateway: atom<HermesGateway | null>(null)
-    }
+// Dev only: park the singletons on globalThis so an HMR re-eval of this module
+// (self-accepted at the bottom) hands back the SAME live sockets/atoms instead
+// of resetting them — that's what keeps the agent session alive across UI edits.
+// `import.meta.hot` is undefined in production, so Vite dead-code-eliminates the
+// entire globalThis branch and prod uses a plain module-local singleton — no
+// globalThis, no Symbol.for. Both realms load the module once, so the container's
+// shape and lifetime are identical either way.
+function gatewayState(): GatewayRegistryState {
+  if (import.meta.hot) {
+    const store = globalThis as unknown as { [STATE_KEY]?: GatewayRegistryState }
+    store[STATE_KEY] ??= createRegistryState()
+
+    return store[STATE_KEY]
   }
 
-  return store[STATE_KEY]
+  return createRegistryState()
 }
 
 const g = gatewayState()