Integrate the frontend http server into pre-release

[MarcoFerreiraPerson]

Features Implemented

• HTTP server (FastAPI)
• Unit tests for the HTTP server (pytest)
• Docker container for building the SQL frontend
• Updated corresponding documentation

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What

Implemented the HTTP server for the Frontend part of the SQL query engine.

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Why

This server provides the required entry point for interacting with the SQL query engine.
It enables future components to send SQL queries and receive results through a standardized interface.

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How

• Built a FastAPI server exposing two endpoints:
  • GET /health – returns the status of the server
  • POST /query – accepts a file or file URI along with a SQL query
• Added pytest-based unit tests to verify:
  • Server availability
  • File upload handling
• SQL frontend logic is not implemented yet (placeholder behavior only)
• Added a Docker container definition to build and run the frontend
• Updated accompanying documentation accordingly

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Testing

Implemented a suite of pytest tests covering:

• Health check endpoint
• Query endpoint with file upload

All CI tests related to these changes pass successfully.

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Closes #17