feat: Complete internationalization and code cleanup

## Translation Files
- Add 11 new language files (es, de, pt, ru, zh, ja, ko, ar, hi, nl, pl)
- Add 100+ missing translation keys across all 15 languages
- New sections: notebook, pagination, ai.batchOrganization, ai.autoLabels
- Update nav section with workspace, quickAccess, myLibrary keys

## Component Updates
- Update 15+ components to use translation keys instead of hardcoded text
- Components: notebook dialogs, sidebar, header, note-input, ghost-tags, etc.
- Replace 80+ hardcoded English/French strings with t() calls
- Ensure consistent UI across all supported languages

## Code Quality
- Remove 77+ console.log statements from codebase
- Clean up API routes, components, hooks, and services
- Keep only essential error handling (no debugging logs)

## UI/UX Improvements
- Update Keep logo to yellow post-it style (from-yellow-400 to-amber-500)
- Change selection colors to #FEF3C6 (notebooks) and #EFB162 (nav items)
- Make "+" button permanently visible in notebooks section
- Fix grammar and syntax errors in multiple components

## Bug Fixes
- Fix JSON syntax errors in it.json, nl.json, pl.json, zh.json
- Fix syntax errors in notebook-suggestion-toast.tsx
- Fix syntax errors in use-auto-tagging.ts
- Fix syntax errors in paragraph-refactor.service.ts
- Fix duplicate "fusion" section in nl.json

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Ou une version plus courte si vous préférez :

feat(i18n): Add 15 languages, remove logs, update UI components

- Create 11 new translation files (es, de, pt, ru, zh, ja, ko, ar, hi, nl, pl)
- Add 100+ translation keys: notebook, pagination, AI features
- Update 15+ components to use translations (80+ strings)
- Remove 77+ console.log statements from codebase
- Fix JSON syntax errors in 4 translation files
- Fix component syntax errors (toast, hooks, services)
- Update logo to yellow post-it style
- Change selection colors (#FEF3C6, #EFB162)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

keep-notes/components/label-filter.tsx

@@ -14,6 +14,7 @@ import { Filter, Check } from 'lucide-react'
 import { cn } from '@/lib/utils'
 import { useLabels } from '@/context/LabelContext'
 import { LabelBadge } from './label-badge'
+import { useLanguage } from '@/lib/i18n'
 
 interface LabelFilterProps {
   selectedLabels: string[]
@@ -22,6 +23,7 @@ interface LabelFilterProps {
 
 export function LabelFilter({ selectedLabels, onFilterChange }: LabelFilterProps) {
   const { labels, loading } = useLabels()
+  const { t } = useLanguage()
   const [allLabelNames, setAllLabelNames] = useState<string[]>([])
 
   useEffect(() => {
@@ -49,7 +51,7 @@ export function LabelFilter({ selectedLabels, onFilterChange }: LabelFilterProps
         <DropdownMenuTrigger asChild>
           <Button variant="ghost" size="sm" className="h-9">
             <Filter className="h-4 w-4 mr-2" />
-            Filter by Label
+            {t('labels.filter')}
             {selectedLabels.length > 0 && (
               <Badge variant="secondary" className="ml-2 h-5 min-w-5 px-1.5">
                 {selectedLabels.length}
@@ -59,7 +61,7 @@ export function LabelFilter({ selectedLabels, onFilterChange }: LabelFilterProps
         </DropdownMenuTrigger>
         <DropdownMenuContent align="end" className="w-80">
           <DropdownMenuLabel className="flex items-center justify-between">
-            <span>Filter by Labels</span>
+            <span>{t('labels.title')}</span>
             {selectedLabels.length > 0 && (
               <Button
                 variant="ghost"
@@ -67,12 +69,12 @@ export function LabelFilter({ selectedLabels, onFilterChange }: LabelFilterProps
                 onClick={handleClearAll}
                 className="h-6 text-xs"
               >
-                Clear
+                {t('general.clear')}
               </Button>
             )}
           </DropdownMenuLabel>
           <DropdownMenuSeparator />
-          
+
           {/* Label Filters */}
           <div className="max-h-64 overflow-y-auto px-1 pb-1">
             {!loading && allLabelNames.map((labelName: string) => {