Add base router

[javidahmed64592]

This pull request refactors the FastAPI server architecture to introduce a pluggable, class-based router system and improve modularity, configuration, and testability. The main changes include extracting routing logic into a BaseRouter abstraction, adding a TemplateServerRouter for core endpoints, and updating the server and tests to support this new design.

API Router Refactor and Modularization

• Introduced a new BaseRouter abstract class that encapsulates API route registration, authentication, and rate limiting, enabling routers to be defined as classes rather than functions. (python_template_server/routers/base_router.py python_template_server/routers/base_router.pyR1-R109)
• Added a TemplateServerRouter implementing health and login endpoints, using the new router abstraction. (python_template_server/routers/template_server_router.py python_template_server/routers/template_server_router.pyR1-R47)
• Updated the main server class (TemplateServer) to use a list of routers, which are configured and registered at startup. The old setup_routes and add_route methods were removed in favor of this new pattern. (python_template_server/template_server.py [1] [2] [3]

Configuration and Initialization Improvements

• The ExampleServer class now accepts an explicit config, config_filepath, and static_dir, and exposes a routers property for registering routers. (python_template_server/main.py python_template_server/main.pyL6-R35)
• The server now loads the API token hash using a configurable environment variable name. (python_template_server/template_server.py python_template_server/template_server.pyL110-R111)

Testing and Fixtures

• Added a test fixture for TemplateServerRouter, including mock rate limiting and configuration, to support the new router-based architecture. (tests/conftest.py [1] [2]

Project Organization

• Created a python_template_server/routers/__init__.py to expose router classes for import. (python_template_server/routers/__init__.py python_template_server/routers/init.pyR1-R6)

These changes lay the foundation for a more extensible, maintainable, and testable FastAPI server by decoupling route logic from the main server class and centralizing security and rate limiting concerns in reusable router classes.