Add implementation planning artifacts for anonymous feedback platform

Complete Phase 0 (Research) and Phase 1 (Design) of implementation planning workflow:

- plan.md: Technical context, constitution check, and project structure
- research.md: Technology decisions for AI integration, file storage, authentication, security
- data-model.md: Domain entities with validation rules and state transitions
- contracts/: API specifications for submission, dashboard, and admin endpoints
- quickstart.md: Developer setup guide with test-first workflow
- CLAUDE.md: Updated agent context with tech stack

All constitutional requirements validated. Ready for task generation phase.

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

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

CLAUDE.md

@@ -0,0 +1,25 @@
+# reklamator Development Guidelines
+
+Auto-generated from all feature plans. Last updated: 2025-10-15
+
+## Active Technologies
+- Python 3.11+ + Flask (web framework), no CSS frameworks, no JavaScript libraries (001-build-an-application)
+
+## Project Structure
+```
+backend/
+frontend/
+tests/
+```
+
+## Commands
+cd src [ONLY COMMANDS FOR ACTIVE TECHNOLOGIES][ONLY COMMANDS FOR ACTIVE TECHNOLOGIES] pytest [ONLY COMMANDS FOR ACTIVE TECHNOLOGIES][ONLY COMMANDS FOR ACTIVE TECHNOLOGIES] ruff check .
+
+## Code Style
+Python 3.11+: Follow standard conventions
+
+## Recent Changes
+- 001-build-an-application: Added Python 3.11+ + Flask (web framework), no CSS frameworks, no JavaScript libraries
+
+<!-- MANUAL ADDITIONS START -->
+<!-- MANUAL ADDITIONS END -->