Feature/change port

[aaryan182]

Related Issue
Fixes #56

Description of Changes
This PR implements proper port configuration handling across the Preswald application ensuring consistent behavior between CLI arguments, configuration files, and default values.

In main.py file
=> Added proper port priority logic in start_server function
=> Implemented environment variable setting for frontend communication
=> Added clear logging messages for port configuration
=> fixed linter errors

In vite.config.js in frontend
=> Updated proxy configuration to use environment variable
=> Added fallback to default port
=> Made proxy configuration more robust with changeOrigin

In cli.py file
=> Updated help text to accurately describe port configuration behavior
=> Added clear documentation about port priority
=> Improved command descriptions

Port Priority Implementation

The changes establish a clear port priority order:

1. Command-line argument (--port)
2. Configuration file (preswald.toml)
3. Default value (8501)

Tested Locally CLI:

=> Installed pytest and pytest-mock
=> Created a test_port_config.py file
=> test_port_priority_cli_argument: Verifies that CLI argument (--port) takes highest precedence
=> test_port_priority_config_file: Verifies that config file port is used when no CLI override
=> test_port_priority_default: Verifies fallback to default port (8501)
=> test_invalid_config_file: Verifies graceful handling of invalid config files

Type of Change

• [✅ ] New feature (non-breaking change which adds functionality)

Testing

Checklist

• [ ✅] My code follows the style guidelines of this project
• [ ✅] I have performed a self-review of my own code
• [✅ ] I have commented my code, particularly in hard-to-understand areas