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/components/note-editor.tsx

@@ -632,6 +632,7 @@ export function NoteEditor({ note, readOnly = false, onClose }: NoteEditorProps)
           {/* Title */}
           <div className="relative">
             <Input
+              dir="auto"
               placeholder={t('notes.titlePlaceholder')}
               value={title}
               onChange={(e) => setTitle(e.target.value)}
@@ -705,6 +706,7 @@ export function NoteEditor({ note, readOnly = false, onClose }: NoteEditorProps)
                 />
               ) : (
                 <Textarea
+                  dir="auto"
                   placeholder={isMarkdown ? t('notes.takeNoteMarkdown') : t('notes.takeNote')}
                   value={content}
                   onChange={(e) => setContent(e.target.value)}