Extract shared filterUserFacingLabels helper

PostAlerts and LabelsOnMe carried byte-for-byte copies of the same
filter excluding system labels and the user's own bot self-label.
Consolidate into one helper in lib/moderation so the two surfaces
cannot drift.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/components/moderation/LabelsOnMe.tsx

@@ -4,6 +4,7 @@ import {msg} from '@lingui/core/macro'
 import {useLingui} from '@lingui/react'
 import {Plural} from '@lingui/react/macro'
 
+import {filterUserFacingLabels} from '#/lib/moderation'
 import {useSession} from '#/state/session'
 import {atoms as a} from '#/alf'
 import {
@@ -34,11 +35,7 @@ export function LabelsOnMe({
   if (!labels || !currentAccount) {
     return null
   }
-  labels = labels.filter(
-    l =>
-      !l.val.startsWith('!') &&
-      !(l.val === 'bot' && l.src === currentAccount.did),
-  )
+  labels = filterUserFacingLabels(labels, currentAccount.did)
   if (!labels.length) {
     return null
   }

src/components/moderation/PostAlerts.tsx

@@ -8,7 +8,11 @@ import {
 import {plural} from '@lingui/core/macro'
 import {useLingui} from '@lingui/react/macro'
 
-import {getModerationCauseKey, unique} from '#/lib/moderation'
+import {
+  filterUserFacingLabels,
+  getModerationCauseKey,
+  unique,
+} from '#/lib/moderation'
 import {useSession} from '#/state/session'
 import {atoms as a} from '#/alf'
 import {
@@ -48,21 +52,20 @@ export function PostAlerts({
   /*
    * Labels that the moderation system already surfaces in this context -
    * whether as an alert, an inform, or a blur handled by ContentHider - should
-   * not be repeated in the "+n" pill. System labels and the author's own
-   * "bot" self-label are excluded the same way LabelsOnMe excludes them.
+   * not be repeated in the "+n" pill.
    */
   const shownCauses = [...alerts, ...informs, ...modui.blurs]
-  const additionalLabels = allLabels.filter(
-    label =>
-      !label.val.startsWith('!') &&
-      !(label.val === 'bot' && label.src === currentAccount?.did) &&
-      shownCauses.every(
-        cause =>
-          cause.type !== 'label' ||
-          cause.label.val !== label.val ||
-          cause.label.src !== label.src ||
-          cause.label.uri !== label.uri,
-      ),
+  const additionalLabels = filterUserFacingLabels(
+    allLabels,
+    currentAccount?.did,
+  ).filter(label =>
+    shownCauses.every(
+      cause =>
+        cause.type !== 'label' ||
+        cause.label.val !== label.val ||
+        cause.label.src !== label.src ||
+        cause.label.uri !== label.uri,
+    ),
   )
 
   if (

src/lib/moderation.ts

@@ -58,6 +58,21 @@ export function labelIsHideableOffense(
   return ['!hide', '!takedown'].includes(label.val)
 }
 
+/**
+ * Filters out labels that are not user-facing: system labels (val prefixed
+ * with `!`) and the user's own "bot" self-label.
+ */
+export function filterUserFacingLabels(
+  labels: ComAtprotoLabelDefs.Label[],
+  currentAccountDid: string | undefined,
+): ComAtprotoLabelDefs.Label[] {
+  return labels.filter(
+    label =>
+      !label.val.startsWith('!') &&
+      !(label.val === 'bot' && label.src === currentAccountDid),
+  )
+}
+
 export function getLabelingServiceTitle({
   displayName,
   handle,