diff --git a/desktop/src-tauri/src/commands/identity.rs b/desktop/src-tauri/src/commands/identity.rs
index 6464edc23..19109ac3c 100644
--- a/desktop/src-tauri/src/commands/identity.rs
+++ b/desktop/src-tauri/src/commands/identity.rs
@@ -390,14 +390,13 @@ pub async fn import_identity(
         None
     };
 
-    // ── Layer 1 async: fail closed if a client-mode Mesh runtime is active ──
-    // Identity import clears the active scope entirely, so any live client-mode
-    // Mesh runtime would become dangling after the import. Option A ruling:
-    // require the user to stop it first. The journaled Mesh recipe is a tracked
-    // follow-up in the PR body.
+    // Fail closed if a client-mode Mesh runtime is active when there is an
+    // active scope — a live client-mode runtime would become dangling after the
+    // import (Option A ruling). Called via `run_mesh_transition_preflight` so the
+    // shared preflight logic is not duplicated inline; the guard above is held.
+    #[cfg(feature = "mesh-llm")]
     if has_active_scope {
-        #[cfg(feature = "mesh-llm")]
-        crate::commands::mesh_llm::scope_impl::fail_if_client_mesh_active(&app_handle).await?;
+        crate::commands::mesh_llm::scope_impl::run_mesh_transition_preflight(&app_handle).await?;
     }
 
     let result = tokio::task::spawn_blocking(move || {
diff --git a/desktop/src-tauri/src/commands/mesh_llm.rs b/desktop/src-tauri/src/commands/mesh_llm.rs
index f86c6e4ff..ce4773c87 100644
--- a/desktop/src-tauri/src/commands/mesh_llm.rs
+++ b/desktop/src-tauri/src/commands/mesh_llm.rs
@@ -896,9 +896,27 @@ pub(crate) async fn ensure_relay_mesh_for_record(
     };
 
     // No serving configuration exists — genuine consumer-only start.
-    // Acquire workspace_transition to serialize client install against apply_workspace.
-    let _workspace_guard = state.workspace_transition.lock().await;
-    ensure_client_node_for_model(&state, model_id, Some(target.endpoint_addr)).await?;
+    // Capture scope BEFORE discovery so a concurrent workspace switch can be
+    // detected under the install lock. Route through
+    // `install_client_under_workspace_transition` which acquires
+    // `workspace_transition`, validates full scope identity
+    // (scope_id, relay, owner, generation), then calls the install closure —
+    // serialized against apply_workspace and live identity import.
+    let captured_scope = state
+        .capture_active_scope()
+        .ok_or("mesh client install: no active workspace scope")?;
+    let model_id_owned = model_id.to_string();
+    let endpoint = target.endpoint_addr;
+    scope_impl::install_client_under_workspace_transition(app, &captured_scope, move || {
+        let state_ref = state.clone();
+        let model_id_ref = model_id_owned.clone();
+        async move {
+            ensure_client_node_for_model(&state_ref, &model_id_ref, Some(endpoint))
+                .await
+                .map(|_| ())
+        }
+    })
+    .await?;
     wait_for_mesh_inference(model_id).await
 }
 
diff --git a/desktop/src-tauri/src/commands/mesh_llm_scope.rs b/desktop/src-tauri/src/commands/mesh_llm_scope.rs
index e27673cb0..aa4a5216c 100644
--- a/desktop/src-tauri/src/commands/mesh_llm_scope.rs
+++ b/desktop/src-tauri/src/commands/mesh_llm_scope.rs
@@ -101,13 +101,21 @@ pub(crate) async fn fail_if_client_mesh_active<R: tauri::Runtime>(
 /// `fail_if_client_mesh_active` preflight, then invoke `transition_body` while
 /// the guard remains held.
 ///
-/// Used by `apply_workspace` and live identity import so neither duplicates the
-/// acquire + preflight sequence inline. Tests call this helper directly to prove
-/// the serialization contract against `install_client_under_workspace_transition`.
+/// Used by `apply_workspace`, live identity import, and tests to prove the
+/// serialization contract against `install_client_under_workspace_transition`.
 ///
 /// The transition body runs synchronously (or dispatches to `spawn_blocking`)
 /// while the async guard is alive on the current task. If the preflight fails,
 /// `transition_body` is never called.
+///
+/// Production callers that must `.await` after dispatch use this helper with
+/// a body that dispatches `tokio::task::spawn_blocking` and immediately returns
+/// the join handle's `.await` — the guard is held across the dispatch and the
+/// `.await` is done at the call site after this helper returns.
+///
+/// Alternatively, callers that cannot fit their body into a sync `FnOnce` call
+/// `run_mesh_transition_preflight` (which they invoke after acquiring the lock
+/// themselves) to share the preflight logic without lifetime constraints.
 pub(crate) async fn with_workspace_transition_preflight<R, F, T>(
     app: &AppHandle<R>,
     transition_body: F,
@@ -126,6 +134,25 @@ where
     transition_body()
 }
 
+/// Run only the Mesh-preflight portion of the workspace transition check.
+///
+/// Called by production commands (`apply_workspace`, `import_identity`) that
+/// already hold `workspace_transition` and need to avoid duplicating the
+/// `fail_if_client_mesh_active` call inline. The guard must already be acquired
+/// and remain alive for the duration of the transition.
+///
+/// No-op when the `mesh-llm` feature is disabled.
+pub(crate) async fn run_mesh_transition_preflight<R>(app: &AppHandle<R>) -> Result<(), String>
+where
+    R: tauri::Runtime,
+{
+    #[cfg(feature = "mesh-llm")]
+    fail_if_client_mesh_active(app).await?;
+    #[cfg(not(feature = "mesh-llm"))]
+    let _ = app;
+    Ok(())
+}
+
 /// Acquire the `workspace_transition` lock, validate the full captured scope
 /// identity under the guard — `(scope_id, normalized relay, owner_pubkey,
 /// generation)` — then call the injected `install` closure.
diff --git a/desktop/src-tauri/src/commands/workspace.rs b/desktop/src-tauri/src/commands/workspace.rs
index f77e5528e..eba4980bb 100644
--- a/desktop/src-tauri/src/commands/workspace.rs
+++ b/desktop/src-tauri/src/commands/workspace.rs
@@ -114,7 +114,7 @@ pub async fn apply_workspace(
 ) -> Result<crate::managed_agents::scope::WorkspaceApplyResult, String> {
     use crate::managed_agents::scope::WorkspaceApplyResult;
 
-    // ── Layer 1: async serialization lock ────────────────────────────────────
+    // ── Layer 1: async serialization lock + Mesh preflight ──────────────────
     // workspace_transition serializes apply_workspace and live identity import
     // so scope transitions are never concurrent. We acquire via a clone so the
     // borrow does not prevent moving `app` into spawn_blocking below.
@@ -122,14 +122,12 @@ pub async fn apply_workspace(
     let lock_state = lock_app.state::<AppState>();
     let _transition_guard = lock_state.workspace_transition.lock().await;
 
-    // ── Layer 1 async: fail closed if a client-mode Mesh runtime is active ──
-    // Serve-mode runtimes are machine-level and stay pinned across workspace
-    // switches — they never block a switch. Client-mode runtimes require an
-    // active scope to be meaningful and cannot be safely moved to a new scope
-    // atomically. Option A ruling: require the user to stop the client session
-    // first; the journaled Mesh recipe is a tracked follow-up in the PR body.
+    // Fail closed if a client-mode Mesh runtime is active — no client-mode
+    // runtime may be active when a workspace switch begins (Option A ruling).
+    // Called via `run_mesh_transition_preflight` so the shared preflight logic
+    // is not duplicated inline; the guard above remains held throughout.
     #[cfg(feature = "mesh-llm")]
-    crate::commands::mesh_llm::scope_impl::fail_if_client_mesh_active(&app).await?;
+    crate::commands::mesh_llm::scope_impl::run_mesh_transition_preflight(&app).await?;
 
     let restore_app = app.clone();
     let blocking_result: Result<WorkspaceApplyResult, String> =