UX Text Improvements: Thinker Module Pages

- Updated page titles to be more descriptive:
  * Prompts: 'AI Prompts Management' → 'Customize Your AI Writer'
  * AuthorProfiles: 'Author Profiles' → 'Choose Your Writing Voice'
  * Strategies: 'Content Strategies' → 'Your Content Strategies'
  * ImageTesting: 'Image Testing' → 'Test Your Image Generator'
  * Dashboard: 'Thinker Dashboard' → 'Your AI Configuration Dashboard'

- Updated navigation tab labels across all Thinker pages:
  * 'Prompts' → 'AI Instructions'
  * 'Author Profiles' → 'Writing Voices'
  * 'Strategies' → 'Content Strategies'
  * 'Image Testing' stays the same

- Updated Prompts page section titles:
  * 'Planner Prompts' → 'Keyword & Topic Instructions'
  * 'Writer Prompts' → 'Article Writing Instructions'
  * Updated descriptions to be more conversational

Part of comprehensive UX text improvement initiative.

frontend/src/pages/Thinker/AuthorProfiles.tsx

@@ -101,9 +101,9 @@ export default function AuthorProfiles() {
 
   // Thinker navigation tabs
   const thinkerTabs = [
-    { label: 'Prompts', path: '/thinker/prompts', icon: <BoltIcon /> },
-    { label: 'Author Profiles', path: '/thinker/author-profiles', icon: <UserIcon /> },
-    { label: 'Strategies', path: '/thinker/strategies', icon: <ShootingStarIcon /> },
+    { label: 'AI Instructions', path: '/thinker/prompts', icon: <BoltIcon /> },
+    { label: 'Writing Voices', path: '/thinker/author-profiles', icon: <UserIcon /> },
+    { label: 'Content Strategies', path: '/thinker/strategies', icon: <ShootingStarIcon /> },
     { label: 'Image Testing', path: '/thinker/image-testing', icon: <ImageIcon /> },
   ];
 
@@ -111,7 +111,7 @@ export default function AuthorProfiles() {
     <div className="p-6">
       <PageMeta title="Author Profiles" />
       <PageHeader 
-        title="Author Profiles" 
+        title="Choose Your Writing Voice" 
         badge={{ icon: <UserIcon />, color: 'blue' }}
         navigation={<ModuleNavigationTabs tabs={thinkerTabs} />}
       />