fix: Add missing typing imports to Module 10 tokenization

Issue: CharTokenizer was failing with NameError: name 'List' is not defined
Root cause: typing imports were not marked with #| export

Fix:
✅ Added #| export directive to import block in tokenization_dev.py
✅ Re-exported module using 'tito export 10_tokenization'
✅ typing.List, Dict, Tuple, Optional, Set now properly exported

Verification:
- CharTokenizer.build_vocab() works ✅
- encode() and decode() work ✅
- Tested on Shakespeare sample text ✅

This fixes the integration with vaswani_shakespeare.py which now properly
uses CharTokenizer from Module 10 instead of manual tokenization.

tinytorch/text/tokenization.py

@@ -21,6 +21,16 @@ __all__ = ['Tokenizer', 'CharTokenizer', 'BPETokenizer']
 #| default_exp text.tokenization
 #| export
 
+# %% ../../modules/source/10_tokenization/tokenization_dev.ipynb 3
+import numpy as np
+from typing import List, Dict, Tuple, Optional, Set
+import json
+import re
+from collections import defaultdict, Counter
+
+# Import only Module 01 (Tensor) - this module has minimal dependencies
+from ..core.tensor import Tensor
+
 # %% ../../modules/source/10_tokenization/tokenization_dev.ipynb 8
 class Tokenizer:
     """