chore: Bump version to 0.7.0

Version updates:
- README.md badge: 0.6.0 → 0.7.0
- cli/pyproject.toml: 0.6.0 → 0.7.0
- backend/pyproject.toml: 0.6.0 → 0.7.0
- sdk/pyproject.toml: 0.6.0 → 0.7.0
- ai/pyproject.toml: 0.6.0 → 0.7.0

Add CHANGELOG.md with comprehensive release notes for 0.7.0:
- Secret detection workflows (gitleaks, trufflehog, llm_secret_detection)
- AI module and agent integration
- Temporal migration completion
- CI/CD integration
- Documentation updates
- Bug fixes and improvements

Update llm_analysis default model to gpt-5-mini

ai/pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "fuzzforge-ai"
-version = "0.6.0"
+version = "0.7.0"
 description = "FuzzForge AI orchestration module"
 readme = "README.md"
 requires-python = ">=3.11"