feat: Add security hardening, agentic coding infrastructure, and test framework

- Add SECRET_KEY and ENCRYPTION_KEY validation on startup
- Implement security headers middleware (X-Frame-Options, CSP, HSTS)
- Add CSRF protection middleware
- Create comprehensive GitHub issue templates and PR template
- Add Makefile with common development tasks
- Configure pre-commit hooks (black, ruff, mypy, bandit, detect-secrets)
- Create docs/CODING_PATTERNS.md with best practices
- Create docs/ERRORS.md documenting all error codes
- Add Architecture Decision Records (ADR) for Celery and Fernet encryption
- Create CHANGELOG.md for version tracking
- Set up pytest test infrastructure with fixtures and factories
- Add sample unit tests for security and config validation
- Create CI/CD workflows (test, lint, security)
- Add comprehensive TODO.md with milestones and progress tracking

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,38 @@
+---
+name: Feature Request
+about: Suggest a new feature or enhancement
+title: '[FEATURE] '
+labels: enhancement
+assignees: ''
+---
+
+## Feature Description
+<!-- A clear and concise description of the feature -->
+
+## Problem Statement
+<!-- What problem does this solve? -->
+
+## Proposed Solution
+<!-- How would you like this to work? -->
+
+## Alternative Solutions
+<!-- Any alternative approaches you've considered -->
+
+## Use Case
+<!-- Describe a specific scenario where this would be useful -->
+
+## Implementation Notes
+<!-- Optional: Technical details, API design, architecture considerations -->
+
+## Acceptance Criteria
+<!-- How would we know this feature is complete? -->
+- [ ] Criterion 1
+- [ ] Criterion 2
+- [ ] Documentation updated
+- [ ] Tests added
+
+## Priority
+<!-- Low / Medium / High / Critical -->
+
+## Related To
+<!-- Link to roadmap items, other issues, or discussions -->