Bump minor version to 3.1.2.0

Version bump to reflect the chunk truncation removal improvement that
completes the model-aware chunking optimization by ensuring users see
full chunk content without truncation.

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

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

Author: jsbattig

src/code_indexer/__init__.py

@@ -5,5 +5,5 @@
 to provide code search capabilities.
 """
 
-__version__ = "3.1.1.0"
+__version__ = "3.1.2.0"
 __author__ = "Code Indexer Team"