Add UI and styling documentation; remove idempotency and logging audits

- Introduced a new document outlining UI structure, reusable template components, CSS variable conventions, and per-page data/actions for the CalMiner application.
- Removed outdated idempotency audit and logging audit documents as they are no longer relevant.
- Updated quickstart guide to streamline developer setup instructions and link to relevant documentation.
- Created a roadmap document detailing scenario enhancements and data management strategies.
- Deleted the seed data plan document to consolidate information into the setup process.
- Refactored setup_database.py for improved logging and error handling during database setup and migration processes.

docs/developer/development_setup.md

@@ -0,0 +1,104 @@
+# Development Environment Setup
+
+This document outlines the local development environment and steps to get the project running.
+
+## Prerequisites
+
+- Python (version 3.11+)
+- PostgreSQL (version 13+)
+- Git
+- Docker and Docker Compose (optional, for containerized development)
+
+## Clone and Project Setup
+
+```powershell
+# Clone the repository
+git clone https://git.allucanget.biz/allucanget/calminer.git
+cd calminer
+```
+
+## Development with Docker Compose (Recommended)
+
+For a quick setup without installing PostgreSQL locally, use Docker Compose:
+
+```powershell
+# Start services
+docker-compose up
+
+# The app will be available at http://localhost:8000
+# Database is automatically set up
+```
+
+To run in background:
+
+```powershell
+docker-compose up -d
+```
+
+To stop:
+
+```powershell
+docker-compose down
+```
+
+## Manual Development Setup
+
+### Virtual Environment
+
+```powershell
+# Create and activate a virtual environment
+python -m venv .venv
+.\.venv\Scripts\Activate.ps1
+```
+
+### Install Dependencies
+
+```powershell
+pip install -r requirements.txt
+```
+
+### Database Setup
+
+1. Create database user:
+
+```sql
+CREATE USER calminer_user WITH PASSWORD 'your_password';
+```
+
+1. Create database:
+
+```sql
+CREATE DATABASE calminer;
+```
+
+### Environment Variables
+
+1. Copy `.env.example` to `.env` at project root.
+1. Edit `.env` to set database connection details:
+
+```dotenv
+DATABASE_DRIVER=postgresql
+DATABASE_HOST=localhost
+DATABASE_PORT=5432
+DATABASE_USER=calminer_user
+DATABASE_PASSWORD=your_password
+DATABASE_NAME=calminer
+DATABASE_SCHEMA=public
+```
+
+1. The application uses `python-dotenv` to load these variables. A legacy `DATABASE_URL` value is still accepted if the granular keys are omitted.
+
+### Running the Application
+
+```powershell
+# Start the FastAPI server
+uvicorn main:app --reload
+```
+
+## Testing
+
+```powershell
+pytest
+```
+
+E2E tests use Playwright and a session-scoped `live_server` fixture that starts the app at `http://localhost:8001` for browser-driven tests.