feat: image AI titles (3 suggestions), describe-images action, pin/list fixes, i18n

- Add image description service + API route for AI-powered image analysis
- Image title generation returns 3 selectable suggestions via TitleSuggestions component
- Add "Describe images" action in AI assistant (individual + collective)
- Fix pin refresh propagation in card and tabs view
- Fix note creation refresh in tabs mode, pass all notes to tabs view
- Add RTL support (dir="auto") on note content elements
- Pass UI language dynamically to AI endpoints instead of hardcoded 'fr'
- Add 18 missing i18n keys in both en.json and fr.json
- Sparkles button on images for AI title generation (bottom-right, pulse animation)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

memento-note/app/api/ai/describe-image/route.ts

@@ -0,0 +1,43 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { auth } from '@/auth'
+import { getAISettings } from '@/app/actions/ai-settings'
+import { describeImages } from '@/lib/ai/services/image-description.service'
+
+export async function POST(req: NextRequest) {
+  try {
+    const session = await auth()
+    if (!session?.user?.id) {
+      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+    }
+
+    const userSettings = await getAISettings(session.user.id)
+    if (userSettings.paragraphRefactor === false) {
+      return NextResponse.json({ error: 'Feature disabled' }, { status: 403 })
+    }
+
+    const { imageUrls, mode, language } = await req.json()
+
+    if (!Array.isArray(imageUrls) || imageUrls.length === 0) {
+      return NextResponse.json({ error: 'imageUrls must be a non-empty array' }, { status: 400 })
+    }
+
+    const result = await describeImages(
+      imageUrls,
+      mode === 'title' ? 'title' : 'description',
+      language || 'fr'
+    )
+
+    // For title mode, return suggestions in same format as /api/ai/title-suggestions
+    if (mode === 'title' && result.suggestions) {
+      return NextResponse.json({ suggestions: result.suggestions })
+    }
+
+    return NextResponse.json(result)
+  } catch (error: any) {
+    console.error('[describe-image] Error:', error)
+    return NextResponse.json(
+      { error: error.message || 'Failed to describe image' },
+      { status: 500 }
+    )
+  }
+}