diff --git a/NucleicRemote/Shared/ApproveFromActivityIntent.swift b/NucleicRemote/Shared/ApproveFromActivityIntent.swift
index ef7c62f..747baad 100644
--- a/NucleicRemote/Shared/ApproveFromActivityIntent.swift
+++ b/NucleicRemote/Shared/ApproveFromActivityIntent.swift
@@ -7,12 +7,18 @@ import NucleicProtocol
 /// "resolve from the lock screen without unlocking" path (docs/APP_INTENTS_OPPORTUNITIES §4.1).
 ///
 /// It lives in the **Shared** group so both the app and the widget extension can reference it in
-/// `Button(intent:)`. The widget extension links no `NucleicProtocol`, so this intent carries plain
-/// `String` ids and compiles its real work only into the app (`#if canImport(NucleicProtocol)`).
-/// That's sound because iOS runs a widget/Live-Activity button's intent in the **app's background
+/// `Button(intent:)`. It carries plain `String` ids and compiles its real work only into the app,
+/// gated on `#if NUCLEIC_APP` (a custom compilation condition set on the app target only). That's
+/// sound because iOS runs a widget/Live-Activity button's intent in the **app's background
 /// process** — where `RemoteStore` owns the live E2EE channel — never in the extension. The
 /// extension-side copy exists solely to satisfy the `Button(intent:)` type reference.
 ///
+/// NB: the guard is `#if NUCLEIC_APP`, *not* `#if canImport(NucleicProtocol)`. `canImport` tests
+/// module findability, not linkage — and because the app builds `NucleicProtocol` into the shared
+/// DerivedData products dir, it's findable from the widget extension too. So `canImport` is `true`
+/// in the extension, which would compile this branch there and fail on the app-only `RemoteStore`
+/// / `IntentError` types. `NUCLEIC_APP` tracks target membership, which is what we actually mean.
+///
 /// Not discoverable in Shortcuts/Spotlight: it's button-only, driven by ids embedded at render time
 /// (a human uses `AnswerApprovalIntent` for the spoken/Shortcuts path).
 struct ApproveFromActivityIntent: AppIntent {