fix(post): show specific role in moderation posting warning

Replace the generic "posting as moderator" label with the effective role
(5chan dev, owner, admin, or moderator) in post and reply forms.

src/lib/utils/__tests__/author-display-utils.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest';
-import { KNOWN_5CHAN_DEVELOPER_ENTRIES, get5chanDeveloperBadge, getAuthorBadge, isKnown5chanDeveloper } from '../author-display-utils';
+import { KNOWN_5CHAN_DEVELOPER_ENTRIES, get5chanDeveloperBadge, getAuthorBadge, getModerationPostingRoleLabel, isKnown5chanDeveloper } from '../author-display-utils';
 
 describe('author display utils', () => {
   it('recognizes the hardcoded 5chan developer addresses', () => {
@@ -61,4 +61,12 @@ describe('author display utils', () => {
       title: 'administrator_of_this_board',
     });
   });
+
+  it('returns the posting warning label for the effective moderator role', () => {
+    expect(getModerationPostingRoleLabel({ address: 'plebeius.bso', role: 'owner' })).toBe('5chan dev');
+    expect(getModerationPostingRoleLabel({ address: 'other.bso', role: 'owner' })).toBe('owner');
+    expect(getModerationPostingRoleLabel({ address: 'other.bso', role: 'admin' })).toBe('admin');
+    expect(getModerationPostingRoleLabel({ address: 'other.bso', role: 'moderator' })).toBe('moderator');
+    expect(getModerationPostingRoleLabel({ address: 'other.bso', role: 'viewer' })).toBeUndefined();
+  });
 });

src/lib/utils/author-display-utils.ts

@@ -51,3 +51,12 @@ export const getAuthorBadge = ({ address, role }: { address?: string; role?: str
     title: isMod ? 'moderator_of_this_board' : 'administrator_of_this_board',
   };
 };
+
+export const getModerationPostingRoleLabel = ({ address, role }: { address?: string; role?: string }): string | undefined => {
+  if (isKnown5chanDeveloper(address)) return '5chan dev';
+
+  const normalizedRole = role?.trim().toLowerCase();
+  if (normalizedRole === 'owner' || normalizedRole === 'admin' || normalizedRole === 'moderator') return normalizedRole;
+
+  return undefined;
+};