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/app/globals.css

@@ -1,6 +1,7 @@
 @import "tailwindcss";
 @plugin "@tailwindcss/typography";
 @import "tw-animate-css";
+@import "vazirmatn/Vazirmatn-font-face.css";
 
 @custom-variant dark (&:is(.dark *));
 
@@ -174,7 +175,32 @@
   * {
     @apply border-border outline-ring/50;
   }
+
+  /* Set base font size on html element - this affects all rem units */
+  html {
+    font-size: var(--user-font-size, 16px);
+  }
+
   body {
     @apply bg-background text-foreground;
+    /* Body inherits from html, can be adjusted per language */
+  }
+
+  /* Latin languages use default (inherits from html) */
+  [lang='en'] body,
+  [lang='fr'] body {
+    font-size: 1rem; /* Uses html font size */
+  }
+
+  /* Persian/Farsi font with larger size for better readability */
+  [lang='fa'] body {
+    font-family: 'Vazirmatn', var(--font-sans), sans-serif !important;
+    /* Base 110% for Persian = 1.1rem */
+    font-size: calc(1.1rem * var(--user-font-size-factor, 1));
+  }
+
+  /* Ensure Persian text uses Vazirmatn even in nested elements */
+  [lang='fa'] * {
+    font-family: 'Vazirmatn', sans-serif !important;
   }
 }