Update README with roadmap, tech stack and project direction

[BytecodeBrewer]

Goal

Update the README to describe the project direction, roadmap, current tech stack, future tech stack and long-term product vision.

Why

The project is moving from a simple FX converter experiment toward a small data/product lab. The README should explain this direction clearly without overselling unfinished features.

Scope

• Clarify the project vision:
  • FX/data analysis product
  • clean Python foundation first
  • database and reporting next
  • LLM/agentic features later
• Describe current status honestly
• Add a realistic roadmap
• Separate current tech stack from planned/future tech stack
• Explain that CLI exists mainly as internal/dev interface
• Mention planned project documentation files

Suggested roadmap section

Phase 1: Local foundation

• Clean Python project structure
• API client
• Error handling
• Logging
• Tests
• Basic conversion and data handling

Phase 2: Data persistence

• PostgreSQL schema
• Historical exchange-rate storage
• API fetch logs
• Basic SQL queries
• Optional DuckDB for local analysis

Phase 3: Analysis and reporting

• pandas-based data processing
• SQL/Python analysis
• Visualizations
• Reports via Markdown, HTML, Excel, Power BI or PDF

Phase 4: Interface

• GUI/frontend or Streamlit/FastAPI prototype
• CLI remains available as internal developer interface
• User-facing workflows move away from CLI

Phase 5: DevOps foundation

• Docker
• Docker Compose for app + database
• GitHub Actions basics
• Optional small deployment

Phase 6: AI/LLM layer

• Summarize analysis results
• Explain anomalies
• Generate report comments
• Keep human-in-the-loop

Phase 7: Agentic layer

• Agent for data checks
• Agent for analysis
• Agent for reporting
• Only after stable data, reports and service structure exist

Acceptance criteria

• README explains current project status
• README separates current tech stack from planned stack
• README includes realistic roadmap phases
• CLI is positioned as internal/dev interface
• Future LLM/agentic features are clearly marked as later-stage ideas
• README references planned contribution/docs files without pretending they already exist

Notes

The README should communicate product thinking, not tutorial chaos. It should show that the project grows from data foundation toward reporting, interface and later AI support.