chore: Release v5.1.3 - Production/Stable Status

Update project status from Beta to Production/Stable on PyPI.

Changed:
- pyproject.toml: Development Status :: 5 - Production/Stable
- CHANGELOG.md: Document status change with justification

Framework has proven stability with comprehensive test coverage
and extensive production usage.

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

Author: silversurfer562

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "empathy-framework"
-version = "5.1.2"
+version = "5.1.3"
 description = "AI collaboration framework with real LLM agent execution, AskUserQuestion tool integration, Socratic agent generation, progressive tier escalation (70-85% cost savings), meta-orchestration, dynamic agent composition (6 patterns), intelligent caching (85% hit rate), semantic workflow discovery, visual workflow editor, MCP integration for Claude Code, and multi-agent orchestration."
 readme = {file = "README.md", content-type = "text/markdown"}
 requires-python = ">=3.10"